I recently installed a second 7870 graphics card. There is no performance increase in games but I get a significant fps increase (80 fps to 120 fps) when running Heaven Unigine benchmark. Is there any reason for this? Could my CPU be bottlenecking my GPU? I have an AMD FX-4170 processor. I have installed all the latest drivers (CCC 13.1) and CAP. The games I've tried it on are BF3 and Skyrim which both run at around 40-50 FPS. I also have them in fullscreen mode.
Hey, I run a AMD A10 5800k and a HD 6670 on crossfire. Getting 70 - 80 fps but then dropping down to 13fps. I disabled cross fire and it runs at about 50fps on "auto" settings with no lag. Some games just dont like crossfiring. I would disable that before investing in another piece of hardware.