Created attachment 103497 [details] dmesg with working acceleration: GPU faults I just looked at my dmesg (with the same running system as described in comment #91) and noticed quite a few "GPU faults" logged there (see attachement). My Xorg.0.log looks clean though (only the EDID information of one of my monitors was printed out waaay after I started X, at timestamps 1705 and 3420. But I believe that was when powersaving switched off the screens).