Bug#451571: Bug #451571 - xserver-xorg-video-intel: uses lots of CPU with Compiz and (new default) EXA
> The intel video driver now uses EXA by default. When using Compiz as
> my window manager, Xorg consistently uses >50% of the CPU when scrolling
> in Firefox or doing other simple (and formerly efficient) operations.
I second this.
I am not sure it is related, but the shadows around the windows are not
smooth with the new xserver-xorg-video-intel
They look like oblong gradient around the windows.