Terrible performance with crossfire 7970

I have a core I7 and two radeon HD 7970 in crossfire and even without AA and Anisotropic the performance in NTW is very bad. I don't understand.

One-core cpu game as per the minimum specs to play the game. The game is the bottleneck, not your computer just like your posts in S2 Tech except NTW is a little older.