Comment 17 for bug 15178

Your log shows that you have composite enabled, which isn't terribly well
supported by fglrx... Can you try disabling composite, re-enabling fglrx, and
also rebooting to make sure the system is in a "sane" state?

(As for making the free "ati" driver faster, it should speed up a bit with
proper direct rendering and OpenGL acceleration if you completely remove the
xorg-driver-fglrx package... Because the package diverts some other system
files, it somewhat wreaks havoc with switching back if you don't remove/purge it)