(In reply to Maciej Gluszek from comment #257)
> @Guram Savinov: I also tried setting DPM + high performance for my HD3650
> and it worked but the fan was still running too loud (not overheating just
> loud).
> 
> Then i installed Kernel 4.0, removed "high performance" settings and it
> works great now. I still have DPM set during boot but no more setting the
> card to be running on high performance. Couple of days and no lockups.
> 
> I'm on Ubuntu.

Maybe turning off DPM (do not set radeon.dpm=1 in kernel parameters) is better
than using DPM with high performance?

What Ubuntu release do you use? How you installed kernel 4.0?