Bug 168470

Summary: kwin compositing high cpu usage
Product: [Plasma] kwin Reporter: Rosetzky Cedric <loacoon>
Component: compositingAssignee: KWin default assignee <kwin-bugs-null>
Severity: normal    
Priority: NOR    
Version: unspecified   
Target Milestone: ---   
Platform: Compiled Sources   
OS: Linux   
Latest Commit: Version Fixed In:

Description Rosetzky Cedric 2008-08-06 06:18:22 UTC
Version:            (using Devel)
Installed from:    Compiled sources
Compiler:          GCC-4.1.2 
OS:                Linux

I didn't find an existing bug report corresponding to my problem so i'm adding one.

I just updated QT, KDE and Nvidia driver at the same time so I don't know which one caused the problem. But since these updates, I have high CPU usage when compositing is enabled.
Before my update, each core of my Core2Duo E8400 CPU were used at about 2 or 3%. Now it's around 25% for each core.

There is no error message, but Ksysguard says that it's Kwin which is "eating" CPU ressources.
Comment 1 lucas 2008-08-06 06:20:15 UTC

*** This bug has been marked as a duplicate of 154270 ***
Comment 2 lucas 2008-08-06 06:25:15 UTC
What versions did you upgrade from and to by the way?
Comment 3 Rosetzky Cedric 2008-08-06 06:38:30 UTC
I dosn't seems to be the same bug. It's not Xorg which uses my CPU ressources but Kwin. Xorg remains at a normal level.

About the updates. I updated QT from 4.4 to 4.4.1. KDE from a 4 days old svn rev, I think the rev was around 840300 to KDE rev 842797. And finally Nvidia driver from 173.14.05 to 173.14.12.
Comment 4 Rosetzky Cedric 2008-08-06 06:57:28 UTC
I just dowgraded the Nvidia driver to 173.14.05 and it didn't change anything. So the problem seems to come from QT or Kwin.
Comment 5 Martin Flöser 2008-08-06 10:27:13 UTC
as you're using nVidia, pls try the following:
activate direct rendering and deactivate vsync in the advanced settings. This solved the high cpu usage for me.
Comment 6 Lubos Lunak 2008-08-22 19:24:36 UTC