I just retested on my CEDAR with fresh git mesa/llvm. bfgminer is still working correctly for 5+ minutes without a single lock-up on my machine. Kernel is 3.11 final with DPM enabled. The following are the only patches that I have applied that are not yet upstream: LLVM: http://llvm-reviews.chandlerc.com/D1449 Mesa: http://lists.freedesktop.org/archives/mesa-dev/2013-August/043932.html http://lists.freedesktop.org/archives/mesa-dev/2013-August/043951.html http://lists.freedesktop.org/archives/mesa-dev/2013-August/043686.html You probably don't need that last patch, since it's targeted at Southern Islands. I honestly don't know if any of those patches would improve anything for you, but it's what I just successfully tested my evergreen with. You may need to do some slight re-basing of the first patch to take into account some of the recent changes in r600g. I do have my 6850 installed in an old Athlon 64 machine at home. I was already thinking of hooking that machine back up (it's in storage at the moment), so I may be able to re-test this on my 6850 in the next few days... assuming I don't get sidetracked by house maintenance issues.