Comment 20 for bug 1293384

Thomas, I'm also having Xorg/compiz CPU usage issues for which I submitted bug report, and I was wondering if you could follow the steps I outlined and see if you get similar results: https://bugs.launchpad.net/ubuntu/+source/xorg/+bug/1337749

Basically on a fresh boot, launch "top" in a terminal to monitor CPU usage. Then launch a Nautilus window and start moving it around, noting CPU usage. Then resize the window, and try moving it around and see what happens with the CPU usage.

For me, CPU usage jumps from 4% to around 30-40% (before/after the resize) using the open source radeon driver. With fglrx it starts higher at around 15-20%, and jumps to 60-70% after resizing. Even just scrolling down a page in Firefox results in ~70% CPU usage.