Comment # 1 on bug 1210208 from Fabian Vogt

> Other application suffer more or less from the same, but it's neglectable.

Which applications?

This sounds like an Xorg or kernel DRM driver bug to me.

Compositing avoids tearing, but it sounds like some driver issues caused kwin
to crash with compositing enabled. Can you try with all default settings, e.g.
with a new user account?