Could be done some kind of white-list?

For example it seems work very well on 6550D APU and without HyperZ performance
really suffer even for old games. There is not much reasons to not enable it
here. I browsed bug reports and non of them is APU related, so maybe give a
shot for these?

I did test on 3.12.18 kernel, with DPM on, GL_VERSION: 3.0 Mesa 10.3.0-devel
(git-23e9f06). Tested SW: KWin with composite, Counter Strike 1.6 (improved
performance), 0AD (also improved speed), glmark2 2014.03 (515 points -> 717).

Thank you