Dane Bouwer said:
the 5970 has two GPU's, does the game support this? maybe this could be the problem, once the one GPU is pulling to much than it will let the other GPU for some "help"....
maybe the game doesn't support dual GPU simultaneous processing?
just my thought
since technically a 5970 is pretty much 2 5850s on one pcb, it doesnt really suprise me that one gpu is basically idling for all intents and purposes, my 5850 maxes out DIRT2 at 1920x1080 on ultra settings, and typically stays around 60 with vsync on, so unless you hit a really rough area i dont see why the 5970 would use both, especially since you are essentially "capping" your framerate, now to the original post, im not sure why you have a sudden decrease in performance, could be many things, but if you installed the card like new then i dont see how it could be a driver issue