I just bought another 7870 for cross firing and i notice that i am getting a very low fps in a lot of games especially mafia 2. I only get about 30 FPS i checked my ATI drivers making sure that i have the most up to date drivers. As well that my crossfire x option is enabled. I downloaded gpu-z and i noticed that one of my 7870 is reaching 99% load and the other 0% i have no clue why this is happening and how to fix this problem.
k so i tried to moved one of the cards down one pcie slot and powered my comp on and it did display picture bios etc. but i was unable to load windows and i tried the same with the second card same thing so i decided to put it all back the way it was before but i was completely unable to load windows for some weird reason what i ended doing in the end i had to completely reinstall windows and reinstall the AMD drivers again for my cards and it detects my cards as crossfire automatically but when i run a stress test it runs at 1600 by 900 at 51 fps on average and still only runs one card 99% and the other at 0% so im back to square one again.
K no more BS i fixed my problem by using an earlier driver apparently the newer drivers still need to be tweaked quite a bit I used the AMD 13.6 beta 2 drivers and it pretty much fixed everything i was able to do a good bench and basically both cards responded the way i expected (IN FULL SCREEN ONLY)so to everybody that is that is having this issue try using using these drivers hopefully it will be your answer aswell