Ok this is why, CSS uses not only processer ram and graphics card..manly runs off gpu and graphics card..but in css i get a constant 120+ FPS Full quality AA on, bloom hdr..etc. But if you have more than 2 gigs of ram in ur comp also, you get about 50+ FPS because its only using memory from the ram not from the hard drive.
Hi on everything, AA on, hdr on bloom
resolution
1640x1080 i think. (Widescreen)