Bug 328781

Summary: Tearing Prevention (VSync) "Automatic" setting does not work with NVIDIA driver
Product: [Plasma] kwin Reporter: Luke McCarthy <luke>
Component: generalAssignee: KWin default assignee <kwin-bugs-null>
Severity: minor    
Priority: NOR    
Version: 4.11.4   
Target Milestone: ---   
Platform: Arch Linux   
OS: Linux   
Latest Commit: Version Fixed In:

Description Luke McCarthy 2013-12-14 02:25:26 UTC
When the "Tearing Prevention (VSync)" setting is set to "Automatic" when using the nvidia binary driver, I get screen tearing (on a GTX 760).

If I set it to "Full scene repaints" or "Re-use screen contents" the tearing goes away.

I would expect the "Automatic" setting to do the right thing, but in this case it does not. This seems to be a common source of frustration for many users who haven't figured out the correct setting.

Reproducible: Always
Comment 1 Thomas Lübking 2013-12-14 05:52:44 UTC
ensure you're not running into bug #322060
the auto-selection on the nvidia blob is "re-use screen content"
Comment 2 Luke McCarthy 2013-12-17 23:43:29 UTC
Ah sorry, I didn't see that bug report because I didn't notice any CPU load issues but setting KWIN_TRIPLE_BUFFER=1 does fix the tearing issue with the Automatic setting.

*** This bug has been marked as a duplicate of bug 322060 ***
Comment 3 Thomas Lübking 2013-12-17 23:57:59 UTC
If you've triple buffering enabled in the driver there'll be no additional CPU load.
See the last dupe comments and if you can provide the measured time on failure (notice that you've to unset KWIN_TRIPLE_BUFFER or the measure won't take place)