Just went back several weeks in git history with xf86-video-ati, libdrm and mesa and the problem still happens.
Furthermore I noticed that it's not only the 3D performance that collapsed. 2D is also affected. Playing a Youtube video was previously no problem at all, now the image is jerky and the system is fully loaded - most of the cycles are burned by X - something is really wrong here....
I'm really at a loss here.
Just went back several weeks in git history with xf86-video-ati, libdrm and mesa and the problem still happens.
Furthermore I noticed that it's not only the 3D performance that collapsed. 2D is also affected. Playing a Youtube video was previously no problem at all, now the image is jerky and the system is fully loaded - most of the cycles are burned by X - something is really wrong here....