Ok first, here are my specs
psu - cooler master v850
mobo - gigabyte ga-790xta-ud4
cpu - phenom ii 1055t 1.4v
gpu - 2x hd 5970
os - windows 7 64bit ultimate sp1
ram - 8gb adata gaming edition
And my here is my problem, both 5970's in crossfire are working in benchmark tests all 4 gpu's show 100% workload in msi, but when i start a game no matter what game it is only one gpu is working in crossfire, when i disable crossfire 2 gpu's work normally at that game and it shows better performance than my crossfire with both cards, so my question is, is it cpu throttling or something else?
Here is what i have tried, removed latest ati drivers with ddu installed, several different ati drivers, but it did not work, the only thing i haven't tried is to install fresh copy of windows, i'm thinking windows 10 because my windows 7 installation is from 2009, i have updated it regularly and never had any problems with it, so i have not reinstalled it till now.