Mining for Ethereum’s Ether (ETH) coins is turning out to be a problem as it is still in its very early stages, it is still hard for non-advanced users to get started with it. Evven when you follow a guide like our guide on How to Mine Ethereum on Windows yuo can get to another challenge like the mining pool refusing your connections. This has happened today with the ethpool stopping to accept new miners resulting in connections for users trying to use new wallet addresses getting refused while all older miners can still continue to use the pool. The problem here is that ethpool is still the only Ethereum mining pool, so now the only alternative for new users is to solo mine – we have prepared a guide on getting started with Solo GPU Mining Ethereum on Windows. With solo mining however the risks are higher, but the rewards can also be higher if you turn up lucky, there is however no point in solo mining with CPU as the hashrate will be pretty low and you will need a lot of luck to hit a block.
We have updated our mining package that includes the geth client for generating a local Ethereum wallet and also needed for solo mining to the latest version, it is compiled for 64-bit Windows. The package also includes two versions of ethminer (also 64-bit only), the standard one with CPU and OpenCL mining as a part of cpp-ethereum and a second one forked to support CUDA as well. Note that the CUDA version can be used to mine with the CPU, OpenCL and CUDA and you should be are able to use OpenCL on Nvidia GPU’s as well. The CUDA miner should work on GPUs with Compute 2.0 or later, but if you are having trouble running the CUDA miner you can try with the OpenCL one, the resulting hashrate should not be much different between the two implementations. Also we have discovered that adding the parameter “–gpu-batch-size 20” (without the quotes) to the CUDA version of ethminer (works with the OpenCL setting of that miner as well) can increase a bit the performance you get, so we have added it by default to the example bat files for the CUDA version. The hashrate improvement is actually pretty small on Nvidia GPU’s, but on AMD cards using OpenCL it can give better results. We got up from about 24.4 MHS on Radeon R9 280X to about 26.5 MHS by adding the parameter, be aware however that this parameter is only available in the CUDA fork of ethminer.
Another interesting tip regarding issues with low hashrate, either local or reported by the pool, is to try deleting the DAG files that are being generated the first time you run ethminer. Sometimes when you are playing with different settings for the miner it seems that the DAG files may not work that well, so deleting them and having the miner generate them again with the latest settings can bring back the usual performance. So if the locally reported hashrate by the miner suddenly drops or the pool reports only a small fraction of what your total hashrate should normally be you can try deleting the DAG files and having them generated again. On Windows you can find them located in the AppData / Local / Ethash folder under your computer’s Username in the Users folder (example: C:/Users/myPC/AppData/Local/ Ethash). You may need to enable the showing of hidden system files first in order to see the needed folders in Windows Explorer if you have not enabled it already.
It seems that ethpool has just stopped accepting new users due to high load on their server, they have posted the following message: “Due too the high hashrate the pool currently does not accept new miners!”. So if you still haven’t started mining there, existing users can continue using the service, so now may just be the right time to try out solo mining.
The ethminer software uses the ethpool mining pool for mining, the pool fee is 2% and there is a flat fee of 0.01 Ether per payout charged with minimum payout of 1 Ether, also the pool is beta and there could be some issues. The geth software contains only CPU miner while ethminer supports CPU (up to about 2 times faster than geth CPU mining), OpenCL GPU mining for AMD (also works on Nvidia) and CUDA GPU mining. You can use OpenCL mining on Nvidia GPUs as well, could work on older GPUs that do not work with the CUDA miner. If you have integrated GPU it can also be detected as OpenCL capable and the miner may try to run on it, so you can try to use the --opencl-platform and --opencl-device command line parameters to avoid the problem.
Do note that ethminer is 64-bit only and you need to have Visual C++ 2013 Redistributable installed (the 64-bit version) as it is compiled with Visual Studio 2013 and CUDA 7.5RC. Note that it seems AMD is currently faster mining Ethereum as compared to Nvidia GPUs and CPU mining is not much worth other than for testing purposes anyway.