After recently crossfiring 2 7970s, I started having issues CoD:MW2 and Mass Effect. Yet other games such as Team Fortress 2 have no trouble at all. While playing Mass Effect my game will frequently freeze, then after awhile my monitors will flash black as if recovering from a display driver crash, and the game will unfreeze. MW2 does the same but much less frequently. Is this perhaps a result of the games stability regarding crossfire, or perhaps that 7970 crossfire recommends a 1050W PSU when I am running it on only 1000W?