Comment # 7 on bug 79806 from Chernovsky Oleg

> One more! If you (or anyone else) don't have the same card, but have some
> similar issue, you should check if the problem is the same or not (i.e. that
> the card does not turn up performance, when needed). Give some 3D load (e.g.
> glmark2), and check /sys/kernel/debug/dri/64/radeon_pm_info.

I'll try it in my spare time and post results here.