I'm getting significant tearing every time I start KDE.
It goes away after I change the 'Scale method' under System Settings > Desktop Effects > Advanced > General Options (The actual setting is not important, but a change is required every time); OR if the OpenGL Compositing type is changed (Again, just a change is needed).
After a reboot, the tearing recurs and the process has to be repeated.
I'm using KDE 4.11.1 (bug has been present since 4.11.0), the proprietary Nvidia drivers (325.15) with OpenGL 3.1 compositing and Raster graphics. The tearing prevention is set to Re-use Screen Content.
Steps to Reproduce:
1. Start KDE
2. Move window with Titlebar drag / Watch video in any player
3. Pronounced tearing in region of movement
4. Go to System Settings > Desktop effects > Advanced > Scale Method and change setting (to anything)
5. Tearing disappears
6. Restart KDE
7. Problem recurs.
*** This bug has been marked as a duplicate of bug 322060 ***