Comment # 4 on bug 1002642 from Max Staudt

If by "crimson driver" you mean fglrx (a.k.a. the old Catalyst driver), that
one is no longer supported.

The system should autodetect your ATI card at install time, and automatically
install xf86-video-radeon. If, for some reason, that didn't happen, your system
will still have full 3D support through xf86-video-modesetting these days.

To check which one is active, look at /var/log/Xorg.0.log - first every driver
will say hello, then the active one will print a slew of lines about the
detected monitor, resolutions, etc.

You can attach that file and I'll have a look.

Do the artifacts still appear on Leap 42.2?