Xorg high CPU usage on scrolling and moving windows
For the last few days I've been experiencing quite odd behavior regarding Xorg. Xorg seems to use about 70 % of CPU when I scroll through a document in Kate, webpage in Opera etc. In KSysGuard I can see that both of my CPU cores have over 50% load. When the system is idling, Xorg uses from 1 % to 8 % CPU. Moving windows exhibits the same behavior.
This happens regardless to compositing or window manager. I tried KWin and OpenBox in KDE 4.5, I also tried running just plain X with TWM, but the problem remains. The problem initially appeared with Xorg-server 1.8.1 and 256.44 drivers, update to 256.53 and Xorg-server 1.9 didn't change a thing. I also tried downgrading to 220.127.116.11 kernel to no avail.
I'm currently running Xorg-server 1.8.1, 256.53 drivers and 18.104.22.168 kernel with BFS and BFQ.
There is another rather strange issue with MPlayer and VDPAU which might not be related. If I play a clip encoded in H264 using VDPAU and HW accel, X uses about 30% CPU (sometimes as much as 50%) when compositing is enabled. Disabling compositing makes X to drop below 5%. MPlayer uses about 5 % CPU all the time. I'm sure I didn't have this issue before.
When interpreting my CPU load percentages, please note that I have a dual-core CPU and I don't use dividing the load by the number of cores, so both cores at full load would read as 200% usage in my case.
My HW conf:
Core2 T9550 2.66GHz
GF 9800M GTS