Comment 3 for bug 1388490

Found the cause, and it's a familiar one.

The issue is this Intel N270 Atom is entering idle state C4 ("deeper sleep" mode) constantly to reduce power consumption. When it does this, it doesn't have enough power to render the screen smoothly.

Workaround:
Keep the CPU awake and in full-power mode. For example: $ while true ; do true; done

Fix:
Yes, I think it is actually possible to fix this in Mir and not mandate a kernel config change. The fix should be to utilize the "autosleep and wake locks" feature that was introduced in Linux kernel 3.5. So we should be able to strategically tell the kernel when not to go into deep sleep and provide us with enough power to render smooth graphics when we need it. The bad news is this is an upstream-Linux feature only, and it's different to what you will find in Android kernels.

http://kernelnewbies.org/Linux_3.5#head-e04ea6fe9005ea057124123d7834624cd445e124
https://lwn.net/Articles/479841/