No vertical sync with NVIDIA

[Mountain Man]

I encountered this problem in 13.04, but I eventually "fixed" it with a fresh install. Unfortunately, the problem has reappeared after upgrading to 13.10.

Anyway, here's the problem:

I have no vertical sync in KDE. When I move windows across the screen or scroll down a webpage, I get really annoying tearing. Vsync seems to work fine in games, however, like Legends of Grimrock and Half-Life 2, which indicates that it's a KDE problem. I have vsync enabled everywhere I can -- in NVIDIA X Server Settings and the KDE control panel -- yet the problem remains. I have all the other 3D accelerated effects, just no vertical sync. Searching on the internet found many people with similar problems but no solutions.

Perhaps I could completely uninstall the drivers and all related configuration files and start with a clean slate. To that end, does anybody have a complete list of the configuration files generated when the NVIDIA drivers are installed and run? Or perhaps somebody has other ideas.

Thanks.

[papa33]

Have you tried

export KWIN_TRIPLE_BUFFER=1

[Mountain Man]

Thanks for that. That at least got me on the right path, and I found this thread on another forum with the solution:

https://bbs.archlinux.org/viewtopic....24765#p1324765

The summary is to create a file called Tearing.sh in /etc/profile.d/:

# /etc/profile.d/Tearing.sh
export KWIN_TRIPLE_BUFFER=1

Another poster suggested that triple buffering doesn't solve all vsync issues and recommended using:

export __GL_YIELD="USLEEP"

Then make it executable with:

chmod +x /etc/profile.d/Tearing.sh

Once that's done, reboot.

The GL_YIELD worked for me, and now vertical sync appears to be working as it should.

Thank your for the push in the right direction.

[GreyGeek]

Ah, true geek wizardry!

One wonders how many other little environmental variable gems lay waiting to be discovered and polished up?