Bug 261314

Summary:	Regression in KWin OpenGL composting - tearing occurs even when vsync is turned on (since KDE 4.6 RC1)
Product:	[Plasma] kwin	Reporter:	Gareth Hart <tgheretford>
Component:	compositing	Assignee:	KWin default assignee <kwin-bugs-null>
Status:	RESOLVED DUPLICATE
Severity:	normal
Priority:	NOR
Version:	unspecified
Target Milestone:	---
Platform:	Ubuntu
OS:	Linux
Latest Commit:		Version Fixed In:
Sentry Crash Report:

Description Gareth Hart 2010-12-26 20:13:37 UTC

Version:           unspecified (using KDE 4.5.90) 
OS:                Linux

Since upgrading to KDE 4.6 RC1 in Kubuntu, composting with KWin is affected by screen tearing, regardless of whether the VSync option in the Desktop Effects settings is turned on or off. The other options within the advanced tab also have no effect. Reinstalling Kubuntu and deleting the ~/.kde folder to start afresh has no effect.

I am also using NVidia proprietary drivers version 260.19.21. Turning Vsync on/off in both the XServer XVideo settings and the OpenGL settings option has no effect.

Reproducible: Always

Steps to Reproduce:
Upgrade to KDE 4.6 RC1 in Kubuntu, ensure VSync is turned on in KWin. Move any of the windows around the screen and watch the tearing occur. Same thing happens with fast motion videos in a web browser.

Actual Results:  
Screen tearing occurs regardless of what the KWin/NVidia OpenGL VSync options are.

Expected Results:  
There should be no screen tearing when moving windows or viewing fast moving video in a browser, as it was in KDE 4.6 Beta 2.

OS: Linux (x86_64) release 2.6.37-11-generic
Compiler: cc

NVidia proprietary drivers version: 260.19.21
Graphics card: Zotac GeForce 8800GT Amp! Edition

Comment 1 Thomas Lübking 2010-12-26 20:24:37 UTC

see the last comments and the patch on the dupe.
you can spare checking gl vsync in nvidia settings, at least for kwin it has close to no effect.

*** This bug has been marked as a duplicate of bug 258971 ***