I can't run it on full settings with an Intel i7 920 and an Nvidia GeForce GTX 480 :C It's just way too good looking!
Are you high or running it at an insane resolution?
If I remember, these are my specs/settings:
AMD Phenom II X4 @ 3.2GHz
Nvidia GeForce GTX 260
4GB of DDR3 1033Mhz RAM
1600x1200
Full Textures
2x Antialiasing
Everything on high except for shadows and water. HQ shadows is turned off.
16x AF.