[Nexus 7 Original Development] danielsf:
I have two nexus 7's, one stock and the other with this kernel. I have just been comparing the two and the stock is a lot smoother when tracking you finger. I have reset them both to make it a fair test and the ui laggs with the one with this kernel. On home screen when moving my finger it just isn't smooth, it feels more ICS like in it's tracking. On the stock it is pretty much perfect. It feels like on the nexus 7 with this kernel it is jumping frames when slowly scrolling. I just wondering could this be a problem with increasing the pixel clock as it I it could mess up the screen refresh synchronization with the ui frame refresh rate that google was claiming was one of the major improvements in "project butter". I have even reversed the circumstances and flashed stock on the other and the 484mhz gpu overclock on what was stock and I got the same results. It defiantly isn't as smooth. Please could you look into this motley. There is defiantly a smoothness difference between stock and this. I have even set it to 1.6ghz and it doesn't help.

Edit: Just shot a video on my s3 scrolling through things on both side by side, and I believe it clearly shows the stock tracking your finger better. It should take about half an hour to upload. The video isn't very good, but notice how one of the nexus 7 seems to skip and jump when scrolling slowly.

Here is the video: http://www.youtube.com/watch?v=7dCKd48dArk

Just doing some research on what can happen when drawing more frames than can be displayed can cause, and I found this:

Source: http://en.wikipedia.org/wiki/Frame_rate#Proposed_higher_frame_rates

Input lag as descibed here maybe the thing that I am trying to describe. Furthermore, I am not alone when describing this lag, as I have noticed a few people mentioning it in Clemsyn's Elite Kernel when I first noticed my problem and did some searching. Maybe we should try a gpu overclock build with stock pixclock and see if the problem goes away?

Edit: I have been doing more tests. I flashed the no OC GPU build and the lag problem decreased but was still there. I then flashed complete stock on the device. Then I flashed your no oc build on my other nexus 7 which was stock and compared the two like I did in the you tube video above. The no oc gpu build still had the little micro stutters when tracking your finger and the now stock one was almost perfect. I think it maybe something to do with the pixclock increase, as in google stated that the ui refresh rate(60fps) was synced with the display refresh rate(60hz) to prevent mirco stutters and uneven ui frame rate. Now that the pixclock has been increased and the max frame rate is now over 60fps, it may have disrupted this method to make the ui less jumpy and uneven. Also, I noticed the higher the overclock, the worse it got, which happens to have a higher max frame rate on each overclock, which could mean more problems due to it being even further away from the screen refresh rate. I don't suppose I could test out a 484/520mhz with completely stock pixclock please? As apart from bench-marking, increasing the pixclock is irrelevant, even if you overclock the gpu and not increase the pix clock you will benefit from it just as much in intense graphics which push the gpu to it's max. Just none graphically intensive benchmarks like quadrant and nenamark 2 would suffer and to show the performance increase you would just have to use a more intense gpu benchmark like basemark es2 which doesn't even get close to 60fps, so the pix clock would never be a limiting factor. What do you think please?