Comment 186 for bug 803943

I also suffer on this problem on an ultra high end laptop with an i7 processor and a nvidia quadro 1000M (proprietary driver activated) graphics card running a clean install of the latest 12.10 builds. There are always two processes comsuming a lot of cpu: Xorg and compiz. At Idle both use around 3% cpu. If i do somthing, it doesn't matter if it is snapping a window, resizing a window, launch a programm or watch a video: compiz climbes up to 50% (very often) and sometimes even up to 118 for a second. This should not be the case. Disabling Unity plugin does not help very much, and disabeling sync to Vblank results in tearing (although cpu goes down a bit).
I hope this bug can be fixed till the release of 12.10, because the Unity interface will be nearly perfect right then. This is a really big performance issue with high importance, because it can make users switch. Compiz and Xorg alone are causing very high CPU usage. KDE actually has a bit better performance concerning moving tasks ans especially snapping (compiz often consumes lot of cpu concerning this). When I play a video in KDE X is about 10% and kwin around 1 or 2 %. In Ubuntu Xorg is about 10% and compiz around 10%.
But I have to admit Compiz is making great progress! I hope that 12.10 brings a lighter compiz!