Patch - FPS

Since the latest patch I haven't been able to play decent due my FPS jumping from like 120-20-40. I don't think the problem is my pc because i never had any problems with it. I tried several things already: reinstalling the game, putting my pc usage to a minumum, using gamebooster...
Could it be my graphic/video card who isn't compactible with crossfire since the latest patch?

Now I'm currently out of ideas.. Any help?