Comment 79 for bug 88815

I just witnessed an odd behaviour. When I unplug the power-cable from my i915-based laptop and the CPU-throttling kicks in (going from 2 GHz to about 800 MHz). Once that happened all the sluggish drawing performace of OpenGL- and cairo-based programs gets smooth as silk again. I'm running a up-to-date Feisty without downgraded libx11. I've currently no idea what's going on and causing this behaviour, but this might be a hint for more xorg/kernel savvy people here to solve the issue.