Massive FPS drops

Hello everyone, I just started playing for the free Steam weekend and am planning on buying it, but I am suffering massive FPS drops. I am able to run the game on ultra and hold 60 fps, but every 30 seconds or so the FPS drops to about 7 and stays there for 5-6 seconds then jumps back up to 60. This happens on ANY graphics setting and in both offline and online play - it even happens just sitting in the menu.



I am running Win 7 64, 16gb DDR3, ATi 8350 Black Series 8-core GPU, and Sapphire Radeon HD7770.