Im having few issues with nVidia driver both the standard 304 and with the 310 beta drivers. The issue is that X starts to use 20-25% CPU when i have for example EVE-Online working (wine) but it happens without eve on too.
Perf Top shows that nvidia.drv.so uses 63% and nvidia uses 21% with the kernel 12% (delay_tsc), not sure how to interpret this though.
But i found that Xorg starts using and the sluggishness in rendering tabs, opening tabs in chromium takes several seconds. Killing compositing does not help allot. Changed to Openbox and xorg usage was down 0-2% most of the time. Jumped only to 15% when moving windows fast on the twinview desktop.
But in general i found out that performance in kwin + nvidia is not what i expected with my GTX260 card.
For me it sounds like a driver issue, since I don’t even get this on my laptop with a onboard gpu from AMD and it would be awesome if i could find a workaround other than switching DE.
I have the same problem here using Gnome 3.6.1, usually the extreme lags can be aided temporarily by restarting gnome-shell or in some cases some other random application.
The patch that mercurycc linked should resolve any performance issues in KWin for stationary windows. KWin is still known to perform suboptimal operations when dragging and moving windows, but we just submitted upstream patches for this also. This is the patches I’m talking about:
I believe KWin will still attempt to grab the server repeatedly when moving windows, which will result in sub-par performance and choppiness, but we’re also working with the maintainers to get that fixed.
I have noticed that on my nvidia system, my desktop will become increasingly sluggish in long KDE sessions. This can be fixed by restarting the plasma-desktop process, so there might be separate issues at play.