Improve scrolling lag in Android
First I would jump into the developer options and play around with rendering settings in there. This is going to pertain to the GPU probably a lot more than the CPU.

You can also enable some helpful rendering overlays to get visual feedback regarding touch areas, rendered areas, and gpu utilization.

Unfortunately I can't say that one particular item or another will fix it so you will have to play around with them until you see some improvement. Things to try:


High performance mode
Force GPU rendering


The next step would be to try to overclock the GPU's which is going to vary by device.

I would suspect that a mobile friendly site would have much less of an issue rendering all the scrolling than a full desktop site. Another option would be to zoom in more and see if that alleviates some of the lag.

Yet another option would be to try out some custom roms on each of the devices that boast smoother performance. The trade off you're looking for is more performance which is usually at the cost of more battery drain. Efficiency is a great thing but I would always prefer stable smooth performance first and then efficiency.

Do you see any difference if you start scrolling from a still screen vs continuous up and down scrolling? (ie not letting the gpu stop rendering) If so, bumping up the minimum clock at least temporarily may improve this area. The performance governor is your best bet for now.

For the M8, I would recommend ViperOne. I run it on my M7 and its very smooth. You can overclock the GPU with built in software. The only thing I see some lag on is when there are a ton of complex button/slider items that need to be loaded which happens to only be on a few pages within the ViperTweaks sub-app.