I'm using KDE SC 4.11 from the ppa on Ubuntu 13.04 with the nvidia proprietary driver 310 on a GTX 660.

When I set the compositing to OpenGL 3.1 and VSync to "reuse screen content" I get an awesome tearing-free desktop. However, when I reboot or relog into KDE I get tearing again until I go into the compositing settings, switch to OpenGL 2.0 and back to OpenGL 3.1.
Is this a bug or am I missing a setting?


Nevertheless, the devs have my deepest respect; KWin 4.11 is the first compositor that manages a completely fluid and tearing-free desktop on nvidia prop. even when playing 60fps videos through mplayer's GL output.

The reboot issue is something which has been reported and is under investigation - see for example this bug report: https://bugs.kde.org/show_bug.cgi?id=322060

Thank you for your quick reply!

I found a temporary workaround in the bugreport you referenced:

Adding 'export __GL_YIELD="USLEEP"' to /etc/profile fixes it.