First Arm Macs: 13-Inch MacBook Pro, Redesigned iMac; Late 2020 or Early 2021 - <AUTHOR> https://www.macrumors.com/2020/06/21/apple-arm-13-inch-macbook-pro-imac/?scrolla=5eb6d68b7fedc32c19ef33b4 <comment><USER2> Often when Apple shifts the rest of the industry follows within 5 years (touch screen smart phones, ultrabooks, high DPI displays). Although Apple has done architecture shifts before with no impact to the rest of the industry (68k -> PPC -> Intel), I wonder if this will be different.

I read in another thread that volume is what propelled x86s popularity. Intel's difficulty with 10nm has created an opening for other fabs and other architectures to catch up. If ARM can be shown to work as a desktop processor, why wouldn't HP, Dell, Asus and the rest make ARM laptops?

<comment><USER3> ARM laptops already exist [https://www.laptopmag.com/articles/surface-pro-x- arm-app-com...](https://www.laptopmag.com/articles/surface-pro-x-arm-app- compatibility)

<comment><USER4> Lol, commercially successful ARM laptops is what the op meant.

</comment></comment></comment><comment><USER5> Possibly stupid question - does Apple switching to ARM mean the death of Bootcamp?

<comment><USER6> Possible so, unless Apple makes the ARM chip run Intel code. Windows is overrated now and only Windows 10 matters at this point in time.

For $150 you can buy a cheap Intel based PC laptop with Windows 10 on it.

I think Bootcamp might work for ARM based Linux and the ARM version of Windows 10. At least Raspberry PIs that are ARM based can run those.

<comment><USER7> Many games still aren't available on Mac, and things like Wine are not nearly as clean of an experience as just installing games in native Windows. I'd guess switching to ARM will set back the progress made in Mac gaming as well.

<comment><USER8> They sent the message they wanted everybody to hear about gaming when they turned the lever on 32bit support

</comment></comment></comment></comment><comment><USER3> Without the ability to run x86 vms, using a MacBook as a developer workstation would seem very limited

</comment><comment><USER9> I hope Windows 10 ARM will be able to to run on these. I think that might be the push W10 ARM needs to get recognized and have more native applications. It would be somewhat ironic too!

</comment><comment><USER10> What is the advantage (for Apple) of the ARM CPU over the Intels? Is it power? Instructions-per-watt? Or just the ability to control one's destiny?

<comment><USER11> Performance per watt is the biggest advantage, Apple will get fast laptops with extremely long battery life. Cost per performance is a very close second, ARM CPUs are a fraction of the cost of Intel CPUs.

It's also speculated that with active cooling ARM will enable high performance Macs at a lower price point. It's very unclear how well they will be able to match AMD and Intel at the highest performance levels.

<comment><AUTHOR> Perhaps a combined SoC with both ARM and x86-64 cores, with independent switching like Apple already has for GPU integrated/discrete graphics switching. I think this would be a convenient middle way through this compatibility challenge.

[https://support.apple.com/en-us/HT202043](https://support.apple.com/en- us/HT202043)

<comment><USER12> That would increase the cost, to include both x86 and ARM processors.

<comment><AUTHOR> Now we know there will be a dev kit, new macOS, and that the new Macs will natively run iOS and iPadOS apps. Rosetta 2 will handle compatibility.

[https://news.ycombinator.com/item?id=23604060](https://news.ycombinator.com/item?id=23604060)

[https://news.ycombinator.com/item?id=23603852](https://news.ycombinator.com/item?id=23603852)

[https://news.ycombinator.com/item?id=23603866](https://news.ycombinator.com/item?id=23603866)

[https://news.ycombinator.com/item?id=23602434](https://news.ycombinator.com/item?id=23602434)

</comment></comment></comment></comment></comment><comment><USER13> I suppose now that Edge is cross platform there's less need to spin up a windows VM to test in IE/Old Edge.

I do worry about software that is highly tuned with hand-rolled assembly (looking at you various video/photo/audio processing apps) and if this is going to be another transition that is mostly seamless, but with enough edge cases to leave people slightly bloodied.

<comment><USER14> I would think that most video, and photo processing apps are using the GPU rather than custom assembly on the CPU since you have hundreds of cores on a GPU.

<comment><USER13> Perhaps - although Audio software tends to still be heavily CPU based.

</comment></comment></comment><comment><AUTHOR> Original title was too long. It was:

First Arm-Based Macs to Be 13-Inch MacBook Pro and Redesigned iMac, Launches Coming in Late 2020 or Early 2021

</comment><comment><USER15> > _Starting in 2021, Kuo says that all new Mac models will be equipped with > Apple processors, and that it will take 12 to 18 months for Apple to > transition to an all-Arm lineup._

So there's not going to be a Xeon Mac Pro in 2023? Are they just going to drop the Mac Pro or do they actually have a rivaling ARM processor?

<comment><USER16> Does it really matter for the Pro line, if there will be something that gives Xeon run for its money? Say twice as fast or twice as many cores for the same price? Once Pro on ARM is out, and it probably will be the last in a lineup, there will be a lot of software with native ARM support. At that point (unless there is some INSANE advantage that Xeons would give), it is pretty much given that it will become ARM. Question is only in how quickly Apple can come up with something that is noticeable beating Xeons performance-wise.

</comment></comment><comment><USER6> I can't wait to see how the price and power compares to the Intel Macs.

<comment><USER15> I expect the price will not budge at all.

<comment><USER11> Apple has target margin levels, they may increase slightly but most of the savings will go to customers. Apple understands that most customers can't justify the higher cost of Macs despite the additional value, they will for sure attempt to use ARM CPUs to grow Mac market share.

<comment><USER17> Apple has ~$100B cash in the bank. If they wanted to increase market share by lowering prices, they could.

<comment><USER15> It's closer to $200B.

<comment><USER11> No, you aren't counting over $100B in debt.

</comment></comment></comment></comment></comment></comment><comment><USER18> Can anyone explain why Apple would be dropping Intel and doing _ARM_ instead, instead of just, you know, doing _their own thing_? I find it hard to believe either that ARM is the (globally optimal) pinnacle of instruction set / CPU architecture possible, and that a $1tn company can afford to spin up its own CPU production line (competitor to Intel, a $250b company) but not its own CPU design department (competitor to ARM, bough by SoftBank for $30b) ?!?

<comment><USER19> The instruction set matters less for performance than people think. But it does matter a lot for the ecosystem: low-level hyper-optimized libraries for certain operations (think BLAS), tooling, developers understanding how to best write for it, etc. Creating all of that will take a long time no matter how much money you throw at it. For ARM, that ecosystem is probably the second best in the world, and in particular Apple has been building it up for themselves for more than a decade since the first iPhone.

Additionally, sharing the ISA means that the ARM reference cores will always be available as a backstop if Apple's custom chips start running into trouble for whatever reason. IIRC, Qualcomm was doing a lot of hopping between full custom cores and ARM reference ones depending on which one happened to work better some particular year.

</comment></comment><comment> jeppesen-io I wonder what docker looks like on iARM. I assume some level of x86 emulation provided by OSX that VirtualBox will run on top

<comment><USER17> Docker on ARM Linux doesnt use x86 emulation, I'm not sure why Docker on ARM macOS would.

edit: I am aware not all Docker containers run on aarch64. But that has been changing already, and presumably would accelerate if Apple goes all in on ARM.

<comment><USER3> > Docker on ARM Linux doesnt use x86 emulation, I'm not sure why Docker on ARM > macOS would.

macOS is not linux, so it will need some form of emulation/virtualization to run "Docker on ARM macOS"

</comment></comment></comment><comment><USER20> Does it mean that Macbooks get touchscreen?

<comment><USER15> Why would it mean that?

<comment><USER21> Presumably because they could then run iOS applications.

<comment><USER15> That basically already exists in the form of Catalyst.</comment></comment></comment></comment>


IPhone 4S with iPhone 4 design, leaked by iTunes - <AUTHOR> http://9to5mac.com/2011/10/01/iphone-4s-with-iphone-4-design-dual-mode-capability-leaked-by-itunes/

<comment><USER2> Can't we postpone all this crap 70 hours and go on what will then be definitive facts?

<comment><USER3> HN is all about speculation and gossip about other people's money, so the answer to your question is "no".

</comment></comment><comment><USER4> I new thinner/larger design would be nice, but I'm totally happy with the iPhone 4 at the moment. It's one of the best built and best looking devices I own.

My friends have various android phones with huge screens. The size is nice but they feel like cheap plastic.

A hardware upgrade with CDMA and maybe NFC with the same design is welcome.

I can wait another year for a new design with the iPhone 5.

<comment><USER5> The only change I'd make is getting rid of the rear glass. It sounded like a bad idea and I have confirmed (twice) that it is a bad idea in practice. It compromises the device for style.

<comment><USER6> I agree. It's _so_ pretty, but my oh my is it slippery. Of course the old 3g and 3gs were pretty slick too. I wish they'd make the apple logo rubber or something just to give it a little more friction. As it is it ends up sliding off of anything that's not exactly level.

<comment><USER7> My iPhone 4 has a couple of velcro strips (sewing section in WalMart) stuck on the back. This really helps with identifying back and front, and not sliding off sofa arms, and also lets me put it down quietly.

Plus it's useful if I want to attach it to things. Just arrange some velcro tie-wraps, and the iPhone will stick right on. Super convenient.

<comment><USER8> This comment is going to ruin my average, but I just had to say: I love it. That is _so_ clever. Hats off to you, sir.

</comment></comment></comment></comment></comment><comment><USER9> iTunes has a new iPhone 4S entry, but it shows a picture of the existing iPhone 4. What does it mean?

"Unless Apple still has the CDMA iPhone 4 as a placeholder image ... we're fairly confident that the iPhone 4S will pack the CDMA iPhone design."

That's a big "unless".

<comment><USER10> I wouldn't agree that it's a big "unless". The 3GS has set precedent for an "S" version meaning nothing more than suped-up internals.

<comment><USER11> I find it highly unlikely, however, that they would use the exact same image: they would change /something/ about it, whether it just be what the wallpaper is, to the angles of the shots. Given that this is actually the same filename being shared from the other product, it seems much more likely that they haven't put the final images in place yet.

<comment><USER12> I dunno - do the 3G and 3GS use identical-looking images? If so, is it actually the same file?

</comment></comment></comment></comment><comment><USER13> I'm slightly disappointed. The iPhone 4 is a beautiful and high quality device, but I have never liked the way the square edges feel in my hand. I would love to see a return to the 3G/S curved back design.

<comment><USER14> I disliked the square design until I started using FaceTime regularly. The perpendicular edges make it trivial to prop the phone up vertically for a call. I don't think it's a coincidence that the design changed when FaceTime was added.

<comment><USER15> I would disagree, why is this not the case with the iPad then?

<comment><USER8> Smart Cover

Imagine how thick an iPad would need to be to stand solidly on its side, unsupported. Bad idea for a tablet, great idea for a phone.

</comment></comment></comment></comment><comment><USER16> I feel bad for Tim Cook if he has to go out and re-announce a 14 month old product with a spec bump. Not a terribly exciting way to publicly start his new job. They also tried this before with mixed results. The 3GS sold fantastically for the first 6 months or so but it was the Q1/Q2 2010 time- frame where Android phones really took off in part because they simply had better hardware. It's possible that will happen again. There are already some higher resolution displays out there, probably quad-core processors by the end of the year or early next year, and LTE support. I can't help but feel like the 4S is going to look very last-generation in a few months and it won't help if it physically re-enforces this by looking last-generation also. It's a risky move when there's so much competition out there.

<comment><USER17> The hardware in an iPhone really isn't that important as long as the interface is responsive. Apple has consistently made choices that ensure that performance can be squeezed out of slower hardware. These include restrictions on iOS development (less abstraction in interface elements because of limited aspect ratios, restrictions on background processes and aggressive memory management) and hardware acceleration and optimization that comes from very limited hardware profiles. That's why an iPhone 4, with it's single 800mhz core, in most instances feels as fast as the dual core, higher-clocked Android phones that have come out since its introduction.

"The 3GS sold fantastically for the first 6 months or so but it was the Q1/Q2 2010 time-frame where Android phones really took off in part because they simply had better hardware."

That isn't borne out in sales numbers. Apple sales continued to grow during Q1/Q2 2010, and in Q2 2010 Apple sold more iPhones than any previous quarter, even with the (very publicly) impending launch of the iPhone 4. Android sales were also growing rapidly during that time, and that is the period where Android unit sales passed up iPhone unit sales. However, that is more likely due to the availability of competitive Android phones on all the rival networks (iPhone was still AT&T only at that point) during the time when smartphones hit mass popularity.

[http://www.zdnet.com/blog/hardware/apple-q22010-financial- re...](http://www.zdnet.com/blog/hardware/apple-q22010-financial-results- record-march-quarter-revenue-and-profit-iphone-sales-more-than-double/8082)

</comment></comment><comment><USER18> 3G, 3GS, 4, 4S

Makes sense - Apple's using an Intel-like tick/tock release approach. Coming out with a brand new industrial design every year is expensive, since Apple opts for glass/aluminum nowadays rather than plastic.

</comment><comment><USER19> If there is only the 4s which is just a souped up iPhone 4, then why did it take so long to provide so little?

<comment><USER20> From what I hear from my insider friends, the next iPhone has actually been ready for months, they just didn't want to release it so close to the iPhone 4. In fact, they are almost done with the next next version of the phone, but don't expect to see it for at lest a year.

Until someone provides some real competition to the iPhone, they really have no reason to rapidly release new models.

</comment></comment><comment><USER21> Maybe Apple is segmenting iPhones into the cheaper and the more expensive version being iPhone 4S and iPhone 5. The iPhone 4S will be enough for most and may feature less space for music and apps (8GB) and the iPhone 5 will be the bigger devices (16, 32 & 64 GB).

</comment><comment><USER22> iPhone 4s, with iOS5. Seems fit that they would come out with an iPhone 5. Anyways, we will see on Oct 3rd.

<comment><USER23> The Apple event is October 4th actually. Also, I think you mean "anyway".

<comment><USER24> _Also, I think you mean "anyway"._

You object to his dialect, but not to his sentence fragment? :) There are some interesting discussions on "anyway", "anyways" and "anywise" out there, but all three forms have been around for centuries.

</comment></comment></comment><comment><USER25> The new case designs have already been leaked, so we already know that it's going to have a different form factor. It won't be the same as iPhone 4.

<comment><USER26> That assumes there's only one new phone. Isn't there still talk of an iPhone 5 too or is that a dead rumor now?

<comment><USER25> Oh, I didn't realize they were separate. I thought iPhone 4S == iPhone 5.

<comment><USER26> It might be. From John Gruber: _I don't know what the new iPhone looks like. I don't even know whether there's only one new iPhone._

<http://daringfireball.net/2011/09/teardrop_skepticism>

And he goes on to talk about the iPhone 4s and the iPhone 5. Apple, as usual, keeps everyone on the edge of their seats.

My personal take is that Apple should just do the iPhone 4s. In head to head sales, the iPhone 4 still kills everyone else. I'd let it get a little staler -- and then drop the iPhone 5 say in June of next year.

They can do the tick-tock, like Intel. One year, new design, next year use better components. And they can have the iPad and iPhone tick/tock on opposing years.

<comment><USER27> If they plan to ship one or two phone models and upgrade them every two years, they had better have lots of patents, because they certainly won't be able to compete in a fair marketplace.

<comment><USER26> John Dvorak has said something similar:

"The problem here is that while Apple can play the fashion game as well as any company, there is no evidence that it can play it fast enough. These phones go in and out of style so fast that unless Apple has half a dozen variants in the pipeline, its phone, even if immediately successful, will be passé within 3 months."

"And its survival in the computer business relies on good margins. Those margins cannot exist in the mobile handset business for more than 15 minutes."

The problem is -- he said it in 2007.

[http://www.marketwatch.com/story/apple-should-pull-the- plug-...](http://www.marketwatch.com/story/apple-should-pull-the-plug-on-the- iphone)

<comment><USER28> Betting against John Dvorak seems like it might be a viable strategy.

<comment><USER29> Betting against John Dvorak is always a good bet.</comment></comment></comment></comment></comment></comment></comment></comment>


Boost your productivity: Cripple your technology - <AUTHOR> http://matt.might.net/articles/cripple-your-technology/ <comment><USER2> "And, with the exception of nethack, there aren't many ways to waste a lot of time at the console."

Clearly, Matt has not yet fully learned the Unix lifestyle!

<comment><USER3> Indeed, irssi or other console IRC clients are very effective time wasters.

<comment><USER4> <http://www.jaredandcoralee.com/CLIapps.html#Games>

</comment></comment></comment><comment><USER5> These productivity hacks always really confuse me. Maybe it's just me.

Here's my logic: If you want to be productive (i.e. you have prioritized the current task/goal above all else), you just do it with full attention. If it's not very important or you can't align the task with a significant outcome, then you will be prone to distractions.

These tips boil down to negatively reinforcing distractions (not being productive) and positively reinforcing accomplishments (being productive). If you have the ability to apply all these reinforcement techniques in the first place, then you have the self-discipline to just do what you should.

Maybe I just personally prefer advice and tools that helps with prioritizing tasks since that tackles some of the underlying issues.

<comment><USER6> It's not just you. This kind of 'advice' has never helped me, I may even say that it harmed me in a way. There is only a single thing you need to be productive: You need to want it enough. Literally nothing else. There is no magical trick that makes you work more. You either do it or you don't. Many will say now "that isn't helpful at all! 'Just do it' isn't helpful advice!"

On the contrary, it is the only helpful advice that anyone could give you. I don't expect people to believe this, I certainly didn't. It takes guts to admit that maybe, just maybe...it's you who is at fault, not the distractions.

<comment> eric-hu I half agree with this. I've employed some of the above productivity tricks when I want to get things done really badly. I was productive.

I've also ignored all of these tricks had equal productivity.

When I don't want to do something, eliminating all familiar procrastination tools will just make me create or find new procrastination tools. I think the best advice is that small sentence in your post "you either do it or you don't". Embracing that mentality, I either do something or I put it behind me and do something else.

</comment></comment></comment><comment><USER7> My tip: put yourself in some situation where work is so difficult or inconvenient it requires your full attention.

Example: your server crashes, two ads are linked incorrectly, your API provider has suddenly started returning 30% 503s. You are at a Bosselman Travel Center in Nebraska with a cell phone.

You won't get more done, but you _will_ feel productive. It's possible to be inspired by the intensity of such endeavors.

</comment><comment><USER4> Personally, the only thing that motivates me when the work is uninteresting is knowing that someone is expecting it. That's why I'm much less prone to procrastination on work I do for people than at college assignments. Blocking sites never helps, I can entertain myself staring at a blank wall.

I do minimize external distractions (IM, SMS, etc), but that's because they annoy me even when I'm interested in the work. I don't know how people can stand all those notifications popping up.

<comment><USER8> _the only thing that motivates me when the work is uninteresting is knowing that someone is expecting it._

I find that to be a real problem in the workplace. An awful lot of employers/managers seem to think that they simply have to hire engineers, and everything will sort itself out. No clear focus or direction is provided, and no feedback is given on tasks completed. Soon, one feels that all work is going into a black hole, the engineer(s) become disinterested, and end up leaving.

</comment></comment><comment><USER9> I hope the irony is not lost on us that most of us are reading this at work...

</comment><comment><USER10> Divorce yourself from all contact and live on a pillar somewhere in the Sinai desert. I think those folks were called anchorites <http://wikipedia.orange.co.uk/wiki/Anchorite> I'm surprised that a connection to the internet is allowed on a more than---oh say weekly basis. As you might guess, I don't particularly agree with the article. Only cure to the problem at hand is self discipline. Anything else will fail...

<comment><USER11> My feeling is that the traditional definition of self discipline is kind of a fake thing. To me, self discipline is knowing yourself well enough to know where you will fail, and taking appropriate counter measures - not being strong-willed or something.

<comment><USER12> As a matter of fact Jim Loehr and Tony Schwartz authors of "Power of Full Engagement" say that the idea of self-discipline (in the form of strong-will) does not lie at the base of productivity. Indeed they say that human being do not have near enough energy to be self-disciplined in that sense for many decisions.

I think that the real value of the article's tips is that as you get used to not going on HN/Reddit or just avoiding other types of procrastination you will get used to not doing that and thus won't do it even if you remove the barriers.

</comment></comment></comment><comment><USER13> We need better productivity tools, not less technology. Much easier to just sign up for RescueTime. And try LazyMeter to focus on your to-do list one day at a time - we believe one of the core causes of procrastination is people not knowing what they're doing (it's easy to trick yourself into thinking you're productive when you're not).

</comment><comment><USER14> I use this free app to block a blacklist of sites that suck my time. You can set it to block for any length of time you want:

<http://visitsteve.com/made/selfcontrol/>

</comment><comment><USER15> Here's what I wrote on the topic three years ago:

"Some notes on how to make the internet more like a book, magazine, or phone than a television. That is, more like a tool than a world:

1\. Do not use iGoogle, FriendFeed or any other service that provides you with "status updates" from a number of services at once. This leads to a condition where "checking your email" becomes "checking everything". Every hour you will find new interesting things that will bifurcate your attention into many worlds. (However, I have the feeling that an iPhone/iPod Touch, which is in a sense a portable iGoogle, would be a positive replacement. Better to check constantly on a non-immersive device...?) [My new opinion on this is that menu-bar style apps allow you to check email/Facebook etc. more frequently, but faster, which can break the habit of checking your email every 5 minutes and performing a full context switch.]

2\. Do not invest yourself in social networks like Facebook. Don't join groups that encourage participation or frequently send out mass-messages. Don't friend anybody that you don't really want to read about. Use your profile as nothing more than a node (don't post anything to your profile that you might someday want to fiddle with). See it as a communication tool: glorified email/chat. Rather than making certain parts of your profile private, make everything public and make sure that anything anybody can see is something that anybody can see. (This means that you must occasionally un-tag photos and delete Wall posts.) Don't add any applications. Don't try to model your real- world social life.

3\. Twitter is cool. It's addictive, but it doesn't take any time. <5 min. to check what your friends have written and update.

4\. Blogs are cool. As long as you're producing content, there's nothing to feel guilty about. The point is not to stop doing drugs altogether, it's to make sure that every time you do drugs, you're using them to enhance your creativity and your relationships.

5\. Use Times for aggregating feeds. Nothing compares. It frees you from the feeling that you have to read every article. Promotes quick scanning, just like a newspaper.

6\. There's nothing to be done about email. It's addictive and time consuming and it's not going away. Make sure that you're not on any corporate mailing lists (Apple.com, stores you've bought stuff from). Filter mailing lists into folders. Practice self-discipline. Don't see yourself as somebody who 'replies within an hour'.

7\. Create a habit of taking notes when you go on a tangent. This will force you to think deeply and remember what you've learned (plus you'll have it stored for future reference). It will also force you to slow down. I use an Instiki wiki running on my server so that I can access it from anywhere (though I'm considering switching back to desktop tools like VoodooPad and DevonThink).

8\. Favor anti-design. Anytime you have any control over CSS, choose a white background with black text and blue links. Or find some other theme and stick to it. Remember, the internet is blue.

9\. When you can, use UNIX (command line). It feels more like a tool for doing tasks than a world.

10\. Make sure that Facebook sends only two types of notification to you: notification for Messages and Wall posts. This way checking your email means checking your email and also checking the only time-sensitive feature of Facebook at the same time, thus allowing you to ignore Facebook."</comment>


Arm brings custom instructions to its embedded CPUs - <AUTHOR> https://techcrunch.com/2019/10/08/arm-brings-custom-instructions-to-its-embedded-cpus/ <comment><USER2> This sounds like an answer to RISC-V, which was designed to have custom instructions since the beginning (to the point of reserving large blocks of the instruction encoding space for custom instructions). AFAIK, most current RISC-V designs target the same product space as the Cortex-M mentioned in this article.

<comment><USER3> I would not say this is on response to riscv. First of all, ARM was one of the very few vendors not supporting before but mainly due to their co-processor model. Second, the reason arm in giving in now is due to new performance requirements for v8-m due to crypto and ml usecases.

</comment></comment><comment><USER4> My interpretation of this (based on what the article says) is that you are providing an opcode->[instructions or microcode?] mechanism?

Which seems unlikely to be correct, because they already have licenses that allow new instructions/features.

So is it actually "this instruction should be turned into these signals to these ports"?

(I'll try to read the white paper once I'm not on a phone)

<comment><USER4> Ok, so based on [https://www.arm.com/why-arm/technologies/custom- instructions](https://www.arm.com/why-arm/technologies/custom-instructions)

It sounds like this is that you get to specify custom RTL for a given opcode, you are still restricted to whatever functionality is in the standard ALU.

The problem I'm having with the public docs is that they all seem to say "you can replace this [hand coded assembly example] with [a custom opcode]", but don't give an example of the actual implementation of the opcode. That would at least show some sense of what is possible.

</comment></comment><comment><USER5> What is old is new again:

"I guess it is one of the disadvantages of VLSI that it's no longer so feasible to add instructions to your machines."

— Richard Stallman, 1986 ([https://www.gnu.org/philosophy/stallman- kth.html](https://www.gnu.org/philosophy/stallman-kth.html))

</comment><comment><USER6> Here's a direct link to their white paper:

[https://pages.arm.com/rs/312-SAX-488/images/Arm-Custom- Instr...](https://pages.arm.com/rs/312-SAX-488/images/Arm-Custom-Instructions- for-Armv8-M_.pdf)

</comment><comment><USER7> How exactly does this work? Is it a poor man's FPGA?

<comment><USER8> It's a standardized design for chip manufacturers to make it easier for them to add custom instructions in hardware to an ARM core and provide toolchain- support for it, not something software-programmable for the end-user.

<comment><USER3> Since op mentioned FPGAs:

Do you recall NIOS custom instructions? It's similar to that in many aspects.</comment></comment></comment>


Show HN: Precursor, a lightweight prototyping tool with real-time collaboration - <AUTHOR> https://prcrsr.com/bucket/10

<comment><USER2> Hi there,

I just fell in love with this!

It's fast and responsive, collaborative and MOST-IMPORTANTLY it's easy to use! Go to the url, boom doc got created for you, link is shareable.

Only thing I'd like to see now is some kind of document explorer and maybe a way to protect documents or make them mine because right now I could theoretically access any document: [https://prcrsr.com/document/1](https://prcrsr.com/document/1)

<comment><AUTHOR> Thanks for the suggestions!

We're definitely planning to make private and moderated documents. Ping me at firstname.lastname@example.com and I'll let you know when it's ready.

For the document explorer, do you want to see the documents that you created or just interesting docs that anybody created? Either way, we just pushed up a way to export a doc as an image by appending .svg to the end of the url--I'm excited about using them as thumbnail previews in the explorer.

We set up a twitter account @prcrsr_app if you want to follow along with our progress.

<comment><USER2> > For the document explorer, do you want to see the documents that you created > or just interesting docs that anybody created? Either way, we just pushed up > a way to export a doc as an image by appending .svg to the end of the url-- > I'm excited about using them as thumbnail previews in the explorer.

Me personally, I'd like to see a list of my own recent modified documents and a way to name them. Like Google Drive for example. I wouldn't integrate a way for looking at other documents before you're not able to "lock" documents so that others can't destroy them.

</comment></comment></comment><comment><AUTHOR> This is a weekend project I've been working on with a few friends. The goal is to build a prototyping tool that lets you express your ideas in a sharable format.

It's built with React.js/Om, datascript and Datomic. They've worked out really well for us. I'm amazed at how often things that seem difficult to build turn out to be fairly easy. Last night I leveraged Datomic's transaction model (implemented by datascript) to add Emacs-style undo in about 30 minutes.

I'm very curious to hear any feedback you have. The url I posted tries to group people in buckets of 10 to show off the collaboration aspect. If you want a page to yourself, just click the "New Document" icon on the left.</comment>


How we used Justin Bieber trend on Twitter to get hits to our startup - Part 1  - <AUTHOR> http://www.geekybuddha.org/blog/2011/07/20/how-we-used-justin-bieber-trend-on-twitter-to-get-hits-to-our-startup-part-1/ <comment><USER2> How was your conversion rate?

I'm guessing the bounce rate for this demographic is pretty hight, right?

link to the bieber page he made: <http://closest.in/justinbieber>

<comment><USER3> I'm guessing a really high bounce rate and in the end, since those very mostly young Bieber fans as he pointed out himself, very low conversion rate.

If this post stays on the frontpage of HN a little longer I'm most certain the conversion rate from this blog article is way higher, although almost a million people visited.

As I can see it actually 4400 out of 850 000 people sent a kiss, and I guess even fewer actually signed up. So that is 0.05% conversion, which I guess is pretty low.</comment></comment>


Power Prices Go Negative in Germany - <AUTHOR> https://www.nytimes.com/2017/12/25/business/energy-environment/germany-electricity-negative-prices.html <comment><USER2> The article doesn't actually answer the questions it purports to answer. Better source: [https://www.cleanenergywire.org/factsheets/why-power- prices-...](https://www.cleanenergywire.org/factsheets/why-power-prices-turn- negative).

Energy markets are artificial markets designed to create various price signals that result in certain incentives on both generation and demand, subject to numerous constraints. One constraint is that demand and supply must balance. The grid can't store much energy. Oversupply can cause grid frequency to go above 50/60 Hz, threatening grid stability: [https://www.e-education.psu.edu/ebf483/node/705](https://www.e-education.psu.edu/ebf483/node/705). Power prices go negative when there is too much generation capacity online at a given instant, relative to demand. That creates incentives for generators that can shut down (like natural gas) to do so.

Negative power prices are not a good thing for consumers. A negative price in the wholesale electric markets does not mean the electricity is "less than free." Obviously, even wind power or solar always costs positive money to generate in real terms. Instead, it signals a mismatch between generation capacity, storage capacity, and demand. In a grid with adequate storage capacity, negative prices would be extremely rare.

<comment><USER3> I think you're missing the critical piece of your explanation of why negative prices aren't good for consumers:

The reason that negative power prices look like they would be good for consumers is that it seems like they should lower their monthly bills. But in practice their bill should stay the same, even if there were significant periods during which energy prices were negative. Why? The negative prices don't indicate that the cost of power production is negative for the power company, so the power company is losing money. The power company has to recoup those losses _somehow,_ and they do it by charging more when power prices are positive.

In order to take advantage of negative power prices, a power consumer would have to dynamically increase their power consumption in response to the negative prices. If they have any significant power storage capacity, maybe they could store power and sell it back to the grid when prices go positive, or maybe turn on their mining rig while prices are negative, if they go negative frequently.

<comment><USER2> All energy costs a positive amount of dollars to produce. Thus, in the long run, the price of electricity must be such that generators recoup their fixed costs, recoup their variable costs, and make some profit that makes the whole endeavor worthwhile.

In an ideal grid, the price of electricity would be a stable amount that hovered around this long-run price.[1] If battery technology was up to par, generators would place batteries between their plants and the grid, and deliver electricity at a predictable rate, which would keep the price stable. Negative rates that deviate dramatically from this price are the sign of a grid in distress. Even though individual consumers might be able to take advantage of these periods of negative rates, that doesn't mean its good news for consumers as a class.

It's like when the power company pays electricity users to shut down during demand spikes. Yes, consumers that can throttle demand during spikes can make money from such events. But if you're seeing the price of electricity spike frequently, that's a sign of something wrong with the grid, not a positive thing for consumers.

[1] This is a simplification, because there's actually more than one energy market involved that generators use to recoup their costs: [https://www.bateswhite.com/media/publication/55_media.741.pd...](https://www.bateswhite.com/media/publication/55_media.741.pdf). But it's easier to explain assuming one market and one price.

<comment><USER4> > All energy costs a positive amount of dollars to produce. Thus, in the long > run, the price of electricity must be such that generators recoup their > fixed costs, recoup their variable costs, and make some profit that makes > the whole endeavor worthwhile.

The only type of cost that strictly determines a price floor is the variable cost. Recuperating fixed costs and profits are based on a revenue _prediction_ which may or may not come true, but once the investment is made it rationally operates until prices descend past the variable cost barrier, regardless of whether long term ROI is positive or not.

What I don't understand is why prices must go negative. A price of zero should be enough to turn off capacity, modulo switching costs (the cost to start or stop a turbine?)

<comment><USER5> It can take a long time to turn some capacity on or off, and not all generators throttle cleanly to zero. Hydro plants can have rough running ranges that cause excessive wear. or might have run-of river flow requirements. Coal plants have huge parasitic loads in the crushers and pulverisers and blowers, and/or poor ability to throttle below a minimum limit.

For any of those reasons, it may make sense for a generator to pay someone else to temporarily take their excess capacity, rather than shut the generator down.

</comment></comment></comment></comment></comment><comment><USER6> Hopefully they'll introduce caps that take power costs to a minimum of zero.

I say this with some experience - here in Northern Ireland we're the world leaders in terribly thought out (and utterly stupid) energy policies, and the economic effects of them.

(Our government recently collapsed, primarily due to a dispute over a programme that saw farmers paid ~£1.12 for every £1 of biomass energy they consumed, with no upper cap. Needless to say, there are empty barns in the middle of nowhere at 30°C inside right now causing a lot of pollution and "making" their owners a fortune. As a result of how much it has cost and is projected to, a lot of spending has just been cancelled, including badly needed hospitals).

So yeah, clean energy is great, when it's combined with sane policy.

<comment><USER7> Something having a positive price means it has value.

Something having a negative price means _getting rid of it_ has value.

A positive price signals that there's a cost to consume something.

A negative price signals that there's a cost to _not_ consume something.

<comment><USER6> Is that the case here, though?

I didn't directly infer from the article that there was a cost to not expending the energy being held in the grid (i.e. does the grid _need_ to expel that excess?). If it needs to expel the excess to consumers, then absolutely the negative pricing makes perfect sense, but I got the impression that this was more a fortuitous set of variables than an intended outcome.

</comment></comment></comment><comment><USER8> It seems like a good first world problem to have, begging for engineers to come up with an elegant solution!

What can a country do with occasional excess power like this?

* Communal/City water pumps run only during periods of excess power in a week

* City managed parking buildings that charge electric vehicles for free during these periods

* Heck city/country runs a data center that would "turn ON" servers only during periods of excess power in grids - to be used for public purpose data munging!

* Run an internet archiver that spins up crawlers only during periods of excessive power..

* Use the excess power to run air purifiers or CO2 absorbers or something else cool for the environment that we would not run otherwise..

What would YOU do if you had free power?

<comment><USER9> > What would YOU do if you had free power?

Build and run a factory that made more solar panels. Enough solar to power civilization, any expected consumption growth, as well as power to capture atmospheric CO2 and sink it underground.

<comment><USER10> If the limiting factor in manufacturing solar panels was power then it would be an exponential industry (manufacture 1 solar panel, use it's power to manufacture 2 and so on).

I'm pretty sure the limiting factor is the materials and the machinery involved.

<comment><USER11> If you can automate all the steps, it's all just the energy and the time. Though solar panels require quite a wide supply chain, it will take some time to fully automate.

<comment><USER9> This was what I was targeting. A fully automated solar harvesting manufacturing assembly. Energy and mass go in, out comes panels that are shipped on autonomous semi trucks to a nearby facility for automated install (automated utility scale install robotics already exist).

<comment><USER12> Not everything hinges on power, there is a lot of chemical processing involved in getting those raw materials and the raw materials to prices these materials and so forth. Like the production of sulfuric acid that we need for virtually everything.

</comment></comment></comment></comment></comment></comment><comment><AUTHOR> I'm curious here about what, if anything, these these negative electricity prices might mean for cryptocurrency mining and transaction processing. How feasible would it be to set up compute infrastructure that "soaks up" the extra power in the German market, but is -- presumably -- idle a lot of the time? For example, is this a good application for distributed networks that piggy-back on top of other peoples' computers (with permission, of course). See, for example, historical examples like SETI@home, Folding@home, and Popular Power.

<comment><USER13> This is theoretically perfectly feasible. Currently, however, the capital costs of mining equipment are so high that it doesn't make sense to keep them offline.

<comment><AUTHOR> And if you don't have to pay any capital costs, because you are running a massive, opt-in, decentralized pool of compute resources that other people own ... ? :-)

<comment><USER14> Most coin mining is not practical on home computing devices. Wasting the power generation in this way isn't necessarily the best investment of the surplus power.

Also... realize that this is power to the local utilities is negative cost - not the power to someone's home. They're still paying retail rates. I would be most disappointed to have the power utility turn on something that causes me to consume more power (be it cryptocurrency or all the lights in my house) when I'm still paying retail rates.

<comment><AUTHOR> Good point about retail rates being very different from wholesale rates.

</comment></comment></comment></comment></comment><comment><USER15> I see this as an important stage of going green:

Recently/Currently: Unpredictable spikes in wind+solar power make it less profitable to run base-load power plants, since they can no longer guarantee profit at 100% of their duty cycle. Cleaner natural gas peaker plants replace the coal+oil baseload capacity.

Currently/Soon: solar+battery costs fall below natural gas costs, so battery- storage systems replace peaker plants.

Near future: The transportation network converts from gasoline to electricity, absorbing spikes in generation.

Further future: baseload is entirely wind+solar, small and moderate spikes go into batteries that are distributed throughout the grid. But because baseload capacity is scaled to typical demand during typical weather, there are periodically very, very large power generation spikes when wind or sun is strong, generating a lot of temporary energy at essentially 0 cost. I hope this power is used to power negative-emission technologies.

<comment><USER16> I'm not quite sure how to precisely calculate the need, however I'm afraid that you are over-estimating battery capacities. Tesla's Giga Factory planned annual battery production capacity is 35 gigawatt-hours (GWh). Assuming one cycle per day, and a life expectancy of 1000 cycles, dedicating all this plant production to replace peaker plants will give you a storage capacity of about 100 GWh.

While non-trivial, it's still dwarfed by US daily electricity consumption: about 11,350 GWh [1]. Not sure how much would be needed for peaks, but 100 GWh sounds small. And the Giga Factory production is not going towards trying to absorb peaks in the US, but in cars used all around the world in non-optimal patterns.

[1] Based on an annual consumption of 4,144.3 TWh in 2015: [https://en.wikipedia.org/wiki/Electricity_sector_of_the_Unit...](https://en.wikipedia.org/wiki/Electricity_sector_of_the_United_States)

<comment><USER17> Tesla batteries might not solve the storage problem on their own, but there are plenty of additional ways to store energy.

Imho up until recently, we didn't even have that much incentive to research and innovate on large-scale energy storage (outside of storing it as fossil fuels), as we would just generate it when we needed it, so no real need to store it, no need to innovate on that front.

But with the abundance of energy created by renewables, we will need to rethink our approach to energy production and consumption, putting more of a focus on storage than was needed before.

<comment><USER16> Indeed, I was specifically talking about batteries. But there are many other ways to store energy. They don't even need to be as efficient as batteries, as long as they are cheap/scalable.

Found an interesting study after some googling: [https://www.lazard.com/media/438042/lazard-levelized-cost- of...](https://www.lazard.com/media/438042/lazard-levelized-cost-of- storage-v20.pdf)

</comment></comment></comment></comment><comment><USER18> Based on the results of the grid battery system in South Australia it looks like this is the next step for Germany.

Add the batteries for peak smoothing and then you can start to take off the more problematic (carbon foot print wise) base load sources.

<comment><USER19> Not being a power engineer, I'm still wondering if/when somebody is going to try to build a grid capacitor bank. Traditional advantages: long lifespan, high charge/discharge rate, low complexity. Traditional disadvantages: large, heavy.

Maybe the cost doesn't work out or something, but seriously, a fixed land power station seems like the ideal use for caps.

They're fundamentally DC, but so are batteries. I wonder if you could make yourself a massive LC tank, and bypass conversion losses...?

<comment><USER18> Wouldn't it be! There are some interesting issues though with capacitors (my current favorite are graphene ones).

At the end of the day, we're talking about charge waiting to be used sitting around in a capacitor. So looking at how much charge and what are the ramifications of that charge 'at rest' as it were, are really interest.

For example, did you know that if you charged yourself negatively with a few dozen Columbs of charge (in a vacuum) you would float off the ground? You would find yourself repulsed from the earth (which has a huge store of electrons holding negative charge). If you tried it in air however you would find yourself the victim of an extremely vicious lightning attack as the positive charge in the air helped itself to your electrons to balance itself out!

Part of the issue of trying to hold so much charge is that as raw charge, it actually exerts quite a bit of force. It can lift you off the ground, it can pull capacitors toward each other, it can deform the very structure you have created to contain it.

The other issue is keeping it from its mate, if nature abhors a vacuum she really really hates two opposite charges separated by a small gap. You need a really good dielectric separating your charge. You can't use air unless you have a _lot_ of separation and the more separation the less charge your capacitor can hold. So the ideal dielectric would be the evil twin of graphene, one atom thick and impervious to any charge transfer at all[1]. The compromise is you can't hold as much charge (which keeps the voltage potential down below the dielectrics failure point) and you are back to using a lot of space.

Batteries in this case work because they store the charge in small chemical compounds that act as 'buckets.' The process of moving charge restructures those compounds taking an electron or two and leaving behind a different chemical structure or an empty bucket. This is a "win" because you never have to hold so much charge in one place that it is either acting mechanically on the mechanism (beyond the chemical bonds) or threatening to convert your insulating dielectric into an unwilling conductor. The down side is that assembling and disassembling the chemical compounds is an imperfect process at best.

Ideally, a grid scale capacitor would have some sort of mechanical/physical way of automatically organizing trillions of small individual capacitors which could be processed through and drained or charged as the needs required. That would make them not quite 'ideal' capacitors, capable of delivering all of their charge in one go, but it would allow you to side step the mechanical and dielectric challenges. You would also avoid the challenge of having a chemical transition that was not be 100.0% reversible.

I am always interested in reading papers on interesting research in this area. There are a couple of labs doing work on 'liquid' batteries where the electrolyte can be charged externally through one chemical process and discharged in the battery through another. Graphene capacitors are also pretty cool but they still need a better dielectric and a way of creating them cost effectively. Patterning a few billion connected in parallel seems to be a research target to try and avoid some of the high K issues. But there are many graphene labs and not many are focused on any one thing so it is harder to find.

[1] Even with that you'll get tunneling as the electrons find their probability function landing on the other side of the dielectric, nothing is ever perfect!

</comment></comment></comment><comment><USER14> A bit dated (2011) though touching on the economies of power generation, "The High-Stakes Math Behind the West's Greatest River" ( [https://www.forbes.com/sites/jonbruner/2011/10/20/the- high-s...](https://www.forbes.com/sites/jonbruner/2011/10/20/the-high-stakes- math-behind-the-wests-greatest-river/) ) is an interesting read.

From the NYT article about Germany:

> At the same time, other mainstays of the country's electricity supply, > especially some coal and nuclear power plants, are unable to dial back > quickly enough, leading to negative prices on electricity trading markets.

From the Forbes article about the Columbia river (Oregon / Washington):

> issue is what happens when too much electricity is on offer. The enormous > supply of hydroelectricity during spring runoff can push electricity prices > to zero—the BPA gives away electricity to local utilities for free when it's > forced to produce more than it wants to. Since wind producers enjoy > production subsidies, they can push rates below zero, effectively paying > other utilities to switch off their generators. Last winter, the BPA told > wind producers under its balancing authority that it wouldn't pay negative > rates to them during high-water events.

This gets more complicated when you also take into account the non-power constraints on hydro generation. Environmental concerns limit how much water can go over the spillway (which hyper-aerates the water and increases turbidity... which is bad for the fish. [http://www.oregon.gov/deq/FilterDocs/Coltmdlwqmp.pdf](http://www.oregon.gov/deq/FilterDocs/Coltmdlwqmp.pdf) gets into this including the water standards act.

> The concentration of total dissolved gas relative to atmospheric pressure at > the point of sample collection shall not exceed 110 percent of saturation, > except when stream flow exceeds the ten-year, seven-day average flood. > However, for Hatchery receiving waters and waters of less than two feet in > depth, the concentration of total dissolved gas relative to atmospheric > pressure at the point of sample collection shall not exceed 105 percent of > saturation;

The interconnectivity of all of these factors is quite interesting to me and one of those things that is much deeper than a simple management of the power market.

</comment><comment><USER20> I've always wondered: is it not possible to simply "unplug" some of the turbines from the grid? Would an "unplugged" turbine that was still spinning result in damage to its self?

<comment><USER21> The problem is that green energy subsidies are paid usually per kWh regardless of the need. They are often way more than the energy price.

So even if your energy price is negative 2cents/kWh, and your subsidy is 10c/kWh then it makes sense to still run despite it causing near carnage on the grid.

And all these contracts are very long terms (20-25 years), so no easy way to change terms.

</comment></comment><comment><USER22> So, I work in this field, and I have to find it really annoying to see the NYTimes miss the big picture.

The price for electricity tomorrow from 12 to 1 was set in the Day Ahead Market already, by all the participants (generator owners, utilities, big consumers.) At that market (making up numbers for the sake of explanation), let's say the utilities together bought 22000 KWH for that one hour. The amount of money changing hands is quanitity times price, let's say at $30 per KWH.

12 o'clock comes around, and for whatever reason, consumers are just not flipping enough switches and consumption is 20000. Now at the Real Time Market, money changes hands to get enough generators to dial back production, and enough big time consumers to dial theirs up.

Some times utilities don't buy 100% of their power on Day Ahead, taking the risk that they can get a decent deal at Real Time for the small amount of top- up they will need. SOmetimes they overbuy because of bad forecasts. That's when negative pricing kicks in.

Back to our example: Consumers only need 20000KWH for that hour. So 2000KWH's worth of dials need to turn. The people turning the dials get paid for it, at that negative price.

But the amount of money changing hands is small compared to what happend the day before when forecasted power was scheduled.

TLDR:This is not a big deal.

<comment><USER23> I'm a bit shocked your first hand explanation was down-voted. Facts should be appreciated even if they do not fit what one would prefer to be the case.

Another fact bit: Germany electricity retail prices were forecasted to go up next year. There is a fair amount of subsidizing of the build-out of renewable energy still going on. Also the network is not geared towards the new energy source distribution and requires investments for which consumers are billed in part up-front before seeing the benefits.

Another fun fact: The subsidies have angered the liberal party (which has become the bearer holder of liberal markets ideology and is anything but left). To stop the build-out they have started putting up significant building permit regulations in NRW, a state where they have recently risen to power. Explaining how the restrictions on land owners fit with their platform requires a few mental twists.

<comment><USER22> I'll admit it was not my best written comment I was rushing to catch a plane.

BTW, here's a live picture of the New England power market, both real time and day ahead. Older nuclear plants require a day's notice to change their power output, so day-ahead is the norm, but some markets also arrange purchases n hours ahead where n < 24 as well.

[https://www.iso-ne.com/isoexpress/web/charts/guest- hub?p_p_i...](https://www.iso-ne.com/isoexpress/web/charts/guest- hub?p_p_id=lmpmapportlet_WAR_isonelmpmapportlet_INSTANCE_6n3S&p_p_lifecycle=0&p_p_state=pop_up&p_p_mode=view&p_p_col_id=column-5&p_p_col_count=3)

</comment></comment></comment><comment><USER24> Negative prices occur all the time in the US. Not every day, but often enough when load is low and the wind is blowing. As more and more renewable are built, this will occur in increasing amounts. We still have to have non-green generation online as wind and solar can massively fluctuate. For the time being, the state commissions help out the utilities via legislation and increasing rates. This isn't some conspiracy, but what you do if you want available power 24x7.

</comment><comment><USER25> Perhaps its time we started to design power-consuming devices to take advantage of fluctuating electricity costs. That would be one application of "the internet of things" that I don't immediately find creepy and pointless. Alternatively, it could simply spur the private investment of increasing battery technology as consumers would have an incentive to simply charge up their own energy supplies to get a reduction in their overall utilities bill.

<comment><USER26> > "Perhaps its time we started to design power-consuming devices to take > advantage of fluctuating electricity costs."

If your goal is to make money, then sure. If your goal is to reduce the damage caused by burning fossil fuels, I'd suggest reconsidering.

A better use of these negative prices is reducing the number of actively used power stations based on fossil fuels. We would need to keep them until further load balancing capacity could be introduced (i.e. until we no longer had the need to turn the polluting power stations back on). The ultimate goal is a flexible power grid that kept environmental pollution to an absolute minimum.

<comment><USER27> If my IOT freezer could reduce the temperature of the freezer by a further 5c when power is negative and let it rise a couple of c when price rises above 1 standard deviation from the median price then the price signals could be used to modulate demand.

This would save me money, and reduce demand on the grid when there is no renewable energy. My freezer would effectively become a battery, storing energy as a reduced temperature. Multiply this across all households and add in other devices like tumble driers and you could have a real impact.

<comment><USER26> > "you could have a real impact"

You could have a real impact on what? Your wallet?

My point is, we ultimately want to reduce demand on non-renewable sources of energy. With that in mind, running additional devices to soak up the excess demand of the current grid is a mistake, as it hides the fact that not all the electricity was truly needed, and therefore gives no incentive for the electricity producers to reduce supply, which means they'll keep running all the non-renewable power plants they currently do.

You may think that the actions of an individual don't add up to much, but collectively they do, so small acts of reducing electricity usage can have a real impact, both on your wallet and the environment.

</comment></comment></comment></comment><comment><USER28> Crypto mining (bitcoin et al.)/incentivized node hosting will figure this whole thing out.

But seriously, civil power generation/storage via solar will allow folks to escape the patchwork rules, regulations, laws, etc. that are already here and coming to a jurisdiction near you. Power utilities may not buy your power but your mining rig will make you crypto that will allow you to escape that control.

</comment><comment><USER29> We need ways to store the excess power. Otherwise, wind and solar use will have their limits. Fossil fuels will need to power half the grid.

"Battery storage capacity, meanwhile, is not yet advanced enough to take in all of the excess generation."

<comment><USER24> Agreed, your comment is accurate. It will be quite a while I think before we get there (my guess is 20 years)

</comment></comment><comment><USER30> This is a process systems issue more so than a market one. The inflexibility of traditional energy sources and unpredictability of renewable energy sources coupled with the inability to store energy conspire against the balance of supply and demand. When there's too much energy suppliers can't simply shut it off on a daily basis nor can they store is for excess use and so to deal with market forces they allow prices to go below zero which helps no one, especially not the consumer. What if we created more flexible energy distribution channels from energy stored and not generated daily? Is this possible?

</comment><comment><USER31> Just as a curiousity. Is this negative power often enough to make a business model of battery supply to the power system feasible?

I mean having a company with a massive bank of batteries. When power goes negative they try to take as much as they possibly can from the network and when it goes positive they try to sell it back at the higher rate. Essentially win-win. You only power up on negative days and you sell when you make money, otherwise you just sit on it. And since you were paid to take the energy in the first place losing it over time when you don't sell isn't a loss because you didn't pay for it at all.

</comment><comment><USER32> I've also heard that negative power prices are an indicator that excessive subsidies are present in the market. Is this true? I think I saw it here on HN in the comments a year or two ago when it happened in Texas.

<comment><USER21> Yes, of course. The German energy grid is one of the most incredibly (over) subsidized grid in the world. Incredibly low wholesale costs, incredibly high retail costs. The difference is the enormous amount of subsidies paid to green energy producers.

If there weren't subsides in play everyone would be going bankrupt.

<comment><USER32> That's a damn shame. I'm "pro whatever is cheapest" energy, and theoretically, that should be renewables like solar and wind. In my opinion, subsidies hurt more than help after the R&D phase of deployment. It makes an investment into the technologies complicated and dependent on regulatory climate.

</comment></comment></comment><comment><USER33> And on German news sites: [http://www.spiegel.de/wirtschaft/service/strompreise- steigen...](http://www.spiegel.de/wirtschaft/service/strompreise-steigen-laut- einer-verivox-analyse-zu-jahresbeginn-noch-weiter-a-1185047.html)

Strom wird zu Jahresbeginn noch teurer

Die Strompreise sind hoch wie nie - und es geht noch weiter: Das Verbraucherportal Verivox rechnet für das kommende Jahr mit einem Preissprung. Obwohl die Versorger Nachlass geben könnten.

</comment><comment><USER34> Why did they go negative instead of zero or just very low? Why did the power company encourage people to needlessly waste electricity? Do excess generated electricity cause problems for the companies? If yes, won't shutting down some generators get rid of the excess?

This is my first questions to the headline. The answer is not obvious for me, but I can't find an answer in the article.

<comment><USER35> All the electricity produced must be consumed, roughly at the same time. It has nowhere else to go.

Shutting down generators is a process that may take hours (or days if it's nuclear) and may be expensive.

<comment><USER34> Ah. Can't you just press buttons to turn off generation on windmills or solar panels for example?

<comment><USER35> You can disconnect solar panels, yes. You can disconnect a windmill turbine from its generator too (what carries a small cost).

You can't just disconnect thermal solar generators, but shutting them down is relatively fast and cheap.

When the price goes negative, it's usually because consumption is smaller than the coal + nuclear supply.

<comment><USER14> Or hydro can't put that much over the spillway because of regulations (environment, down stream flooding, etc...) - it has to go through the powerhouse.

Or (for hydro again), there was a release of water upstream in anticipation of demand (it takes a few hours to go from the Grand Coulee to the bottom dam) and that demand didn't appear (or other sources produced more - such as a sunny and windy day).

Hawaii and its island power issues also has the "well, you can turn off the centralized solar power systems, but the distributed residential ones are difficult to curtail."

</comment></comment></comment></comment></comment><comment><USER36> Creating the electricity market was one of the biggest mistakes humans have ever made because it created the potential for Enron. And now we don't even question the existence of the market. There's a lot of good history to discover here. The merchants of power by John Wasik is a good place to start.

</comment><comment><USER37> Do consumers really get paid to consume? Never heard of anyone having a negative item on the electricity invoice.

<comment><USER38> These are negative wholesale prices, it's in the internal electricity market, which consumers don't really interact with.

</comment></comment><comment><USER8> Ironically, the "related coverage" article was how Puerto Rico was still without power..

</comment><comment><USER39> Article says price was $60/megawatt-hour, and that the inversion lasted "for much of Sunday and the early hours of Christmas Day".

How much current can a typical industrial user draw from their connection?

Maybe there's a market for large internet connected resistors.

</comment><comment><USER40> Isn't this supposed to be solved by better batteries? I'm confused why the supply of energy matters, unless there's a limited amount of time to use it.

I'm not an electrical engineer, so if anyone understands this better, please correct me :-)

<comment><USER24> Batteries simply don't really exist to store grid level amounts of energy. You have to stack lots and lots of batteries which costs lots and lots of money and still only stores something like ~10 MW when we have 1500 MW coal plants. Electricity is used immediately, so we really can't economically store it in the levels we need. In the future (this is just starting to occur), large batteries will charge (as a load) when the price is low and discharge (as a generator)when it is high which allows the owner to make money and helps the grid as these resources can provide power nearly instantaneously. Right now they're small and few in number, but they will get bigger and more prevalent assuming battery technology continues to get better.

-Source electrical engineer in this industry

<comment><USER41> Isn't 10 MW a unit of power and storing energy would be in MWhs or Joules? I understand that the grid needs to balance the power it is using, but to provide that power over time you need to store energy. Surprised an "electrical engineer in this industry" would use these terms, but maybe I just don't quite grok the lingo. An explanation would be great.

<comment><USER24> You're correct, but in the industry we really just talk in terms of Power at the transmission grid level and usually in millions of watts or MW. So if a coal plant is currently generating 2000 MW and you have a battery that can only consume 5 MW or 0.25%, then that isn't very much storage. Put another way, let's say the load in your region is 60 GW and you have 200 MW of energy storage. That is only a tiny fraction of storage relative to what the demand is.

<comment><USER42> So the main constraint on the battery is throughput, not storage capacity?

<comment><USER24> Nope, the main issue is indeed the fact that it can't store a whole lot of energy (also important that they can't maintain a high output for too long), but we still talk in MW as that is what we're primarily concerned with (MW flow on a line going over the line's rating...not having enough generation (MW) to meet load (MW)...etc). Saying a battery can't store enough MW isn't scientifically accurate, but it is the slang of the industry if you will. If you worked in the water industry they're probably very concerned with water flow rates. In high voltage transmission we're concerned with the flow of power (MW (real power) & MVAR (reactive power))

</comment></comment></comment></comment></comment></comment><comment><USER43> It would be cool if there were some home automation devices that monitored power prices and they would atomatically turn on the washing machine and such when the prices went negatice + there was stuff to wash in the machine for example.

<comment><USER44> I don't want that when I'm not there to put wet clothes in the dryer. And although I once had a combination washer/dryer it didn't work well.

</comment></comment><comment><USER7> > What causes negative prices?

> Basically, when the supply of power outstrips demand for it.

What does this even mean? Why would demand for _being paid_ to use power be finite?

It doesn't make sense to view demand as separate from the price of consumption.

<comment><USER2> I'll ship you 100 tons of refined uranium, _and_ I'll pay you $50 for it. But you've gotta be able to take delivery in the next 20 minutes.

<comment><USER7> Are you trying to make the point that consuming electricity is as difficult as storing uranium?

I'm not making a general statement about negative prices. I'm making a statement about being paid to connect a resistor to the end of a power cord.

<comment><USER35> Of course it's much easier. If it was as difficult there would be big companies living just on properly getting rid of electricity.

But it being easier does not make it free. The price is negative exactly because it costs the generating company something to put a resistor at their side. If you have a resistor around that is cheaper, you can get some nice payment out of using it.

<comment><USER7> Why doesn't the power producer just disconnect the generator from the grid? A turbine spinning isn't a problem in and of itself.

I don't disagree with you in theory, but in practice I don't believe that it's cheaper to send out power over the grid, and pay people to consume it, than it is to just not produce it in the first place.

<comment><USER35> The spinning energy MUST be consumed. Otherwise the turbine will accelerate until it breaks, what may take a block away from some city.

Powering down generators take some time, and powering them back up costs quite a bit (both vary widely from one tech to another). For short durations it is just cheaper to pay somebody to take the energy.

</comment></comment></comment></comment></comment></comment><comment><USER45> [https://medium.com/@datarade/the-germans-and-their- renewable...](https://medium.com/@datarade/the-germans-and-their- renewables-c9263f10b33e)

</comment><comment><USER46> and other countries still suffer from clean energy resources. Only because of economic interests for energy sales. In some countries the environment is being destroyed only for some hydropower plants, here is an example: [http://www.ecoalbania.org/ebrd-confirms-negative-impacts- of-...](http://www.ecoalbania.org/ebrd-confirms-negative-impacts-of-albanian- hydropower-plants-on-people-and-the-environment/)

</comment><comment><USER33> Yes, I think it's negative for me that the energy prices are rising.

I'm in Germany and the local news here is different from the Utopia I have to read on Hacker News and Reddit.

</comment><comment><USER47> If you have to pay for the grid to take the electricity you generate, the sensible thing to do is stop generating it, even if your costs are all fixed.

</comment><comment><USER48> The real question is would the bill in the end be lower like this or with a positive energy price, but no green-power taxes?

</comment><comment><USER49> Now that we've seen negative interest rates and negative power prices, what's next?

</comment><comment><USER50> So, is Germany going to pay me for mining BTC/ETH/XMR? :D

</comment><comment><USER51> What kind of energy consumer adjusts their electricity usage based on price?

Seems like this doesn't apply to households - people will just switch stuff on when they need something, they probably don't even monitor prices. I'm guessing this is good for energy-intensive industries that have large battery storage capacity?

*didn't read, paywall

</comment><comment><USER52> If they remade The Graduate, I think the key industry would be: Batteries

</comment><comment><USER53> The fun thing is that three-phase EV charging is common in Europe. Renault Zoe even support 40kW+ charging.

</comment><comment> grey-sunshine Time to mine coins in Germany...

</comment><comment><USER54> how is this sustainable in the long term?

if the energy companies are paying their customers, won't the companies run out of money eventually?

and if they run out of money, then won't they have to be subsidized by the government? and if that happens, isn't that basically people paying taxes, which go to the electric company, which go back to the people?

<comment><AUTHOR> Yes, very large government subsidies created the current market situation in Germany. But, note that "very large" is only relative to typical subsidies of wind and solar in other countries. Also, all electricity markets in developed countries are pretty much completely regulated and the economics of electricity are determined much more by a combination of regulation and indirect subsidies than they are by anything remotely resembling a simple definition of market forces.

In the United States, for example, we have an extremely complicated mixture of local and state-level economic, infrastructure, and supply regulations, environmental regulations that are mostly federal (though also state), zoning, eminent domain, and other kinds of permitting. Then, alongside all those, we have massive subsidies of electricity distribution infrastructure, extraction of coal and oil, transportation, and "homeland security." Finally, we also have relatively small subsidies for wind and solar.

Germany made a policy decision some years ago that public subsidies of renewables would create large positive social externalities. So, yes, the money goes around in a circle, but -- to over-simplify -- in theory creates more money (technology development, improved resistance to economic shocks, jobs, public health) and better outcomes of various other kinds (public health, reduction of climate change risks of various kinds, reduction of risk from nuclear plants, perceived electoral advantages by the political parties in power) as it goes around.

</comment></comment><comment><USER55> Germany has

1) one of the highest prices per kWh for the normal consumer

2) prices are still increasing [http://www.spiegel.de/wirtschaft/service/strompreise- steigen...](http://www.spiegel.de/wirtschaft/service/strompreise-steigen-laut- einer-verivox-analyse-zu-jahresbeginn-noch-weiter-a-1185047.html)

3) produces more CO2 than France.

So what's the news?

<comment><USER56> 1) Related to how the EEG is more a subsidy of energy-intense industry rather than regenerative energy, at the expense of the consumer.

2) "Die meisten Stromanbieter halten an ihren aktuellen Preisen fest, und 78 Versorger senken ihre Preise sogar im Schnitt um 2,2 Prozent. Zugleich aber heben 64 Versorger ihre Grundtarife im Schnitt um knapp drei Prozent an" \--> Most utilities keep their prices fixed, 78 reduce prices by ~2.2%, 64 increase by ~3%.

3) More than France (nuclear), Spain (nuclear, wind), Sweden (nuclear, hydro) and Norway (hydro). It is unsurprising that countries heavily invested in nuclear and hydro produce less CO2.

Germany's energy policy is far from perfect, but probably one of the most future-proof in Europe (which costs money). France will have huge issues with decommissioning in the next decade; nuclear is not a silver bullet.

<comment><USER55> "Germany's energy policy is far from perfect, but probably one of the most future-proof in Europe (which costs money)."

Really? Germany has one of the LEAST future proof energy politics. I would like to see a country that actually has more than a 2 years energy plan and would invest in something meaningful, like Thorium reactors.

<comment><USER57> Germany invested into Thorium in the second half of the last century. Turned out to be a bad investment.

<comment><USER55> Because it was not developed to the final stage?

Worst investment yet, was solar Energy.

PS: Fixed this for you. Sorry, did not know you are a bullshitter!

It started generating electricity on April 9, 1985, but did not receive permission from the atomic legal authorizing agency to feed electricity to the grid until November 16, 1985. It operated at full power in February 1987 and was shut down September 1, 1989.[1]

[https://en.wikipedia.org/wiki/THTR-300](https://en.wikipedia.org/wiki/THTR-300)

</comment></comment></comment></comment></comment><comment><USER58> Of course, when Capitalists read this article, it is bad news for them because they can no longer make money off people. Better stick to oil and coal for maximum profit! #MAGA

/s

</comment><comment><USER59> Germany actually needs to pay other nation states around it to take the energy they can't use (they don't want it). Using the energy intelligently (demand managment) only lowers smoothes the energy spikes of renewable energy only by 11% (when you do it monthly, on a daily base its nearly nothing.) Pump stations are a good idea but the amount of pumpstation we would need only for the current German electricity demand exceeds already what you could build in all of Europe.

Currently when there is a lot of wind we stop coal burning power plants and the government pays its owner for what they could have been produced in that time. Because stopping the plant makes it more inefficient, there are some fix costs around it to operate it.

See this interesting video about the topic (its in German sorry): [https://youtu.be/ZzwCpRdhsXk](https://youtu.be/ZzwCpRdhsXk)</comment>


VCs and MCs - <AUTHOR> http://vcsandmcs.com/

<comment><USER2> Jerry Yang should not be mentioned in the same line as the god (Nas).

Nas is like Mark Cuban. Hot back in the day; picked some fights with chumps, called them out, continued to be on fire.

Jerry Yang is like Vanilla Ice or maybe Milli Vanilli. Did it big in a new way, everyone loved him, then clearly slipped and was exposed; not a one-time thing, but perpetual like the Oyster rollie.

What I wonder: who is the Suge Knight of the VC world? Steve Ballmer? The Skype guys?

</comment><comment><USER3> Forgot Ashton.

And Eminem is Sequoia.

<comment><USER4> Wouldn't Sequoia be more like Roc-A-Fella or Def Jam or something?

<comment><USER2> Sequoia is EMI or Universal. Been in the game since the beginning, play in multiple genres (they invested in a bunch of restaurants, life sciences, etc., not just rap). Their hip-hop/tech business is Def Jam.

Paypal is the Wu Tang Clan. Awesome as a team, split off to do awesome solo projects too, but still linked up through the 36 chambers and able to form like voltron.</comment></comment></comment>


Mark Zuckberg's Non-Apology: Facebook Screwed up with Privacy. But Keep Sharing - <AUTHOR> http://mediamemo.allthingsd.com/20100524/mark-zuckbergs-non-apology-facebooks-privacy-policy-missed-the-mark-but-not/?mod=ATD_rss <comment><USER2> I'd say this is too little, too late, but not in the obvious way.

People are not leaving Facebook en masse right now, nor will they likely any time soon. But the Facebook vs. privacy meme has broken into the mainstream—I mean, it's literally on the cover of Time. Whether they realize it or not, a lot of people are reacting to this. They won't do anything as drastic as quitting Facebook, but they'll become more self-conscious. They'll start to post a little less and text a little more.

There won't be a Facebook exodus. Just a gradual weaning-off by users who don't even know they care about privacy, but are simply reacting viscerally to a vague mistrust of the company. Facebook won't implode, it'll just become less relevant. Like Yahoo, it'll be around for some time to come, but just as most of us haven't expected competitive search results from Yahoo for years, most of us will never really expect Facebook to safeguard any information we give it.

<comment><USER3> Sounds kind of like the "The Elves are Leaving Middle Earth" effect. Though with users, rather than employees...

[http://steveblank.com/2009/12/21/the-elves-leave-middle- eart...](http://steveblank.com/2009/12/21/the-elves-leave-middle- earth-%E2%80%93-soda%E2%80%99s-are-no-longer-free/)

hn discussion: <http://news.ycombinator.com/item?id=1007750>

</comment></comment><comment><USER4> It's a shame, but the best thing to do with Facebook now is to treat everything as public regardless of privacy settings.

Now if you'll all excuse me, I'm off to update my status to "I'm a team- oriented go-getter who is passionate about delivering value to my employer".

<comment><USER5> The best thing to do with _the internet has always been_ to treat everything as public.

<comment><USER6> People keep saying this, but the point is that Facebook got traction to begin with because it was highly private (only open to a small number of Ivy League colleges), and even later had strict privacy settings. Many people who joined never intended to sign up for a public service at all, and many still don't realize that the privacy level has shifted gradually from a kind of gated community all the way to Twitter.

If they had started the service today advertising the settings they have now, I think they would have trouble getting users.

<comment><USER5> Even if they kept the privacy settings intact, I think my point would still be true because of basic network effects.

In the beginning, only other college students were on. Now that FB has spread out to the world at large, my FB social network is pretty close to my actual social network. A friend of mine has account, but hardly uses it pointing out, "What am I going to say on Facebook? I'm friends with my _mother-in-law_." I'm not as restricted a user, but I still don't say much.

</comment></comment></comment></comment><comment><USER7> I think he's totally disingenuous. Yeah, we get it, you want to connect people around the world. At least be honest and say you want people to share more and more information so you can make money off of it.

He talks about being too granular with regards to privacy settings. Who is this op-ed aimed at ? Joe Average Facebook user is not going to know what he means by granular...

<comment><USER8> > _At least be honest and say you want people to share more and more > information so you can make money off of it._

Assuming that profit-maximizing decisions must be harmful for customers seems pretty intellectually lazy to me. You can't see any ways in which encouraging users to share more thoughts with more people could make the product more interesting to use?

> _He talks about being too granular with regards to privacy settings. Who is > this op-ed aimed at ?_

Most Washington Post readers know what granular means.

<comment><USER7> I wasn't assuming that profit-maximizing decisions must be harmful for customers. Of course it would make the product more interesting. I just think he completely ignored what Facebook stands to gain monetarily and completely framed his argument as Facebook being altruistic.

</comment></comment></comment><comment><USER9> Zuck's email to Scoble sheds some light on how they (FB) are trying to make this situation better. They want to react with actual product changes that sound like they are coming soon. ([http://scobleizer.com/2010/05/23/when-do- you-throw-a-ceos-pr...](http://scobleizer.com/2010/05/23/when-do-you-throw-a- ceos-privacy-under-the-bus/)) \</comment><comment></comment><comment></comment><comment></comment><comment></comment><comment></comment><comment>---

Hey, We've been listening to all the feedback and have been trying to distill it down to the key things we need to improve. I'd like to show an improved product rather than just talk about things we might do. We're going to be ready to start talking about some of the new things we've built this week. I want to make sure we get this stuff right this time. I know we've made a bunch of mistakes, but my hope at the end of this is that the service ends up in a better place and that people understand that our intentions are in the right place and we respond to the feedback from the people we serve. I hope we'll get a chance to catch up in person sometime this week. Let me know if you have any thoughts for me before then. -Mark

<comment><USER10> I throw up in my mouth a little every time someone refers to Zuckerberg as "Zuck" in a public forum.

</comment></comment><comment><USER11> It's a shame that the company claims that Mark wrote the op-ed piece in the WaPo, when it was clear he did not.

You can tell because he used his company's boilerplate mission from press releases as his opener.

More proof that the leadership doesn't care... talking in those old-fashioned newspapers is a job for PR goon.

</comment><comment><USER12> I agree... It seems pretty evident that the media attention of the past few weeks has been largely artificial. "Self promoters" are right on the mark.

You can see it in the arguments that are being made, primarily it boils down to this: Facebook has too much data on people, and that's scary.

But that's not new, FB, and all social networking sites have been collecting intimate information on users since the beginning of web2.0, the 'new' issue is supposed to be the default privacy settings. Being techies, if we are concerned about privacy, we can easily turn it off. Does it really matter that much to you that other people are sharing their information?

I'm as envious as anyone of Facebook's success. But there'll be better, more profitable battles to fight.</comment>


Entrepreneurs: should you celebrate the milestone of raising money? - <AUTHOR> http://www.startupswami.com/2011/09/hell-yes-you-should-celebrate-raising.html

<comment><USER2> If you only celebrated when you IPOed or sold, most entrepreneurs would never celebrate, and those that did would celebrate once, twice in their lifetimes. Celebrate...then get back to work.</comment>


Rpmalloc – A lock-free memory allocator - <AUTHOR> https://github.com/rampantpixels/rpmalloc <comment><USER2> Looks like they are missing jemalloc in the benchmarks, which would be good to see.

I think the simplicity of a 1300 line allocator is very alluring. At that level it should avoid bloating small programs and is hopefully easy enough to understand if digging in to it.

Also it looks like it is split up into 3 files. consolidating it to a single header file C library would be very nice.

One oddity is the 16 bytes alignment. 64 bytes is the false sharing boundary in x64 so I'm surprised to see this in a concurrent allocator, but maybe I've misunderstood exactly what that means here.

<comment><USER3> I'm going to add jemalloc, lockless and scalloc in the benchmark comparisons soon(ish).

Regarding the files, only rpmalloc.[h|c] is needed. The malloc.c file is just for overriding the malloc family of entry points, and provide automatic init/fini glue.

The 16 byte alignment is just a note that all returned blocks are naturally aligned to 16 byte boundaries due to the fact that all size buckets are a multiple of 16 bytes internally. It is needed for SSE instructions, which is why I mention it.

<comment><USER4> Fair would be a comparison single-threaded to ptmalloc2 (glibc). I assume the slowdown will be ~5%.

And the size granularity is split into 3 (small, medium, large) which is fine, but other's have finer granularities. So benchmarks with object systems would be nice, not just random data.

<comment><USER3> There already is a benchmark against glibc single threaded, compile the rpmalloc-benchmark repository linked in the readme and run the runall script. Compare rpmalloc 1 thread case against crt 1 thread (with crt being the C runtime, i.e glibc in this case).

Graphs and analysis for a Linux system will be added soon, but a spoiler:

rpmalloc 22.7m memory ops/CPU second, 26MiB bytes peak, 15% overhead

jemalloc 21.3m memory ops/CPU second, 30MiB bytes peak, 33% overhead

tcmalloc 20.4m memory ops/CPU second, 30MiB bytes peak, 32% overhead

crt 13.5m memory ops/CPU second, 24MiB bytes peak, 7% overhead

rpmalloc is faster and has less overhead than both jemalloc and tcmalloc, and a lot faster than glibc at the cost of extra memory overhead.

The reasoning behind the granularities is that 16 bytes is a reasonable granularity for smaller objects (below 2KiB in size). Medium sized requests (between 2KiB and 32KiB) have a 512 byte granularity, while large requests (up to 2MiB) have a 62KiB granularity.

If you have a suggestion for additional benchmark models I would be happy to add an implementation for it.

<comment><USER4> Ouch, so this looks like the final coffin into ptmalloc2, and esp. a shout to emacs, which still hasn't finished their portable dumper. But not much missing there, should be ready soon. (I got a not working branch on my GitHub) Hope glibc will adopt this soon.

</comment></comment></comment></comment></comment><comment><USER5> Remember kids, "lock-free", does not always mean faster, it just means lock free.

Example: Lock-free linked lists are great spiky write consistent read situations, but in high-write situations they probably aren't any better than locked linked lists.

</comment><comment><USER6> They don't mention anything about memory fragmentation..

</comment><comment><USER7> Pretty graphs but insufficient analysis, not even a mention of fragmentation in the readme.

<comment><USER3> What specifically would you like to know? I would be happy to elaborate more in the readme if you can explain in more detail what you mean with "insufficient analysis". The reason I posted about it on twitter in the first place was that I wanted feedback and comments on what to improve.

(Btw, I'm the author of the library)

<comment><USER7> Sorry for the terse (and let's face it, slightly unintentionally mean) comment, I just meant that the most interesting aspect of an allocator is not simply its performance, but how it copes with adverse conditions. Yours is already lockless, so that sounds positive already w.r.t. multithreaded performance, but how about when faced with classical allocation patterns likely to cause fragmentation (alloc 2kb, alloc 2kb, free 2kb, alloc 3kb, rinse repeat), and suchlike.

I've never had a desire to deviate from my underlying library's libc allocator, but the principle reason for that (aside from potential for mismatched malloc/free calls due to integration errors), is that I know this stuff is a dark art to nail correctly, and I'm opening myself up to all kinds of potential unknowns by discarding the finely tweaked (although potentially not the most efficient) libc allocator that's been getting patched on to handle adversity for the past 20-30 years.

I'd expect documentation of this sort to appear in the readme, even if just to make mention of another allocator this one is patterned on, where I could maybe go digging for further information around failure cases

This is just a conservative engineer talking, I've never actually written my own general purpose heap allocator, although I understand the design of a few, but perhaps not sufficiently to understand the motivation behind the design (e.g. the kinds of failure cases the design is hoping to avoid). Just more interested in how it's likely to break my app :)

<comment><USER3> Thank you for the clarifications, I will definitely improve the documentation w.r.t trouble cases, fragmentation and similar allocators.

The goal is of course not to replace the standard allocator, but rather to offer an alternative for those cases where the standard allocator performs poorly.

</comment></comment></comment></comment><comment><USER8> I don't see it mentioned, so does anyone know: Can I use this in parallel with malloc? Meaning, can one part of my program use this for allocating memory, while another uses the standard library malloc/free?

<comment><USER9> If you implement the pmr interface and use pmr container types[0] then yes.

1\. [http://en.cppreference.com/w/cpp/memory/memory_resource](http://en.cppreference.com/w/cpp/memory/memory_resource)

</comment></comment><comment><USER10> Does is support allocating memory from HugePages? I couldn't find anything but it should be easy to add for *nix systems as it is already using mmap to request memory from the kernel.

<comment><USER3> It does not, at the moment. Feel free to create an issue about it on the github repo, or even submit a PR if you're feeling creative.

</comment></comment><comment><USER11> Seems interesting; but what happens when 1 thread allocates memory, passes it to another thread and ends? There does not seem to be a way to change ownership of a memory block?

<comment><USER3> Memory blocks are owned by the span (the page-aligned larger bucket of blocks) they belong to. While a span is in use (at least on block is allocated) it is indeed owned by the heap that allocates the block. When the span is completely freed, ownership is released.

In your case, the block will be marked as free for allocation. If it is the last used block in that span, the span will eventually be returned to the global cache and reused by other heaps/threads when the owner thread ends. If the span is still used, it will remain in the heap until the heap is picked up by another thread. Heaps are reused as threads are joined and created (i.e number of allocated heaps are the maximum number of concurrent threads since process started).

The worst case is that one thread allocates blocks, hands them off to other threads then ends, and that the process never creates additional threads. In this case, the spans will remain mapped and unused. I have planned to allow other threads to pick up and collect spans from unused heaps at some point to solve this.

<comment><USER11> that's pretty cool. Is there a way to track progress on reuse (like an issue I can follow)?

<comment><USER3> [https://github.com/rampantpixels/rpmalloc/issues/6](https://github.com/rampantpixels/rpmalloc/issues/6)

</comment></comment></comment></comment><comment><USER12> Anyone has measured what takes to free a big amount of small reserved blocks at once, e.g. free 10^8 blocks of 16 bytes?

<comment><USER2> Are you doing something where you are doing one hundred million small allocations that all get freed at once?

If so, I'm going to make a bold claim that there are better ways to manage that memory than a general purpose allocator.

<comment><USER12> It was just curiosity for that corner case. Obviously, for handling many small memory elements, it is better to avoid calling allocators as much as possible, e.g. using one linear allocation for all the elements, and using realloc() with geometric resize heuristic (i.e. instead of realloc(new_size), doing realloc(new_size * 1.50)).

<comment><USER2> That many allocations probably shouldn't even be allocations in the first place. Realloc is not going to make things better, it copies the memory in anything but very tiny allocations.

<comment><USER12> Realloc, if well implemented, does not copy (using virtual memory stuff).

<comment><USER13> In this case would it work similarly to having single big mmap and counting on kernel allocating pages on first write? So for most cases you would only have a single mmap call and multiple page faults (as it would always be the case). I assume that most allocators do mmap for big allocations so it does not need to be called directly.

I lately tried very naive synthetic test to check when realloc will return different address (meaning that it had to copy). My system started swapping, but it did not return different address. I did not know that realloc works like that, but why wouldn't it.

<comment><USER14> > check when realloc will return different address (meaning that it had to > copy)

What faragon is referring to is that this assumption is incorrect. The virtual address changing does not imply the memory was copied. On linux for example it could have been remapped with mremap(2).</comment></comment></comment></comment></comment></comment></comment>


Why Python? - <AUTHOR> http://www.linuxjournal.com/article/3882

<comment><USER2> Needs a (2000) in the title.

And I'm curious, what current events prompted this particular blast-from-the- past?</comment>