thx for tuning in!
I'm not using Compiz, but KDE/KWin 3.5.7. Specifically, I can observe the slowdown when moving a konsole window that has (pseudo-) transparency enabled (i.e., the screen background image under the konsole is copied with decreased luminance). When I hold my mouse cursor still for a short time, the konsole background is updated, and that's when the entire GUI freezes (with 100% CPU).
This was not happening with an older version of the driver. I think it was 8.40, but unfortunately I can't go back.
After doing rpm --erase for 8.452 and reinstalling 8.40 from the rpm all I get is a black screen .
So it seems I'm stuck with slow 2d
After rebooting twice, the behavior is back to normal - no slowdown anymore. Could this be related to the fact that I have an LCD hooked to my docking station's DVI port.