Since the last patch there is a Problem with FPS.
The Grafikcard only use an idle state to play the Game (Most can only see it on High settings since idle is enough to handle Medium settings with 50+ fps).
AMD Powercolor HD7870 PCS+ Vortex II (used Catalyst 13.8 beta 2)
I had to change my "Power Control Settings" +20 to fix this.
Power Control raises the TDP to increase the amount of voltage the card can use when under load.