Okay so I recently built my new computer everything working great until I try and play Deus ex: Human Revolution. Just in the menu's I've been getting 5-10 fps which is horrible all the settings are as low as they can go and still the same problem. My specs should easily handle this. I can get 60 fps in Arma 2 and Batman Arkham asylum this has really confused me.
Use a program like HWMonitor to check if the GPU's temperature increases while you're running the game. That way you could tell if it's even using the GPU. Or if it's loud enough, you could just try to hear the fans speed up