Well it's getting rapidly better, object detail, draw distance and AA seem to affect fps most assuming you have Intel quad core at 3.5ghz plus
Visibility 1500
Objects 800
Shadows 100
Cloud Very High
Shadow High
Particles Very High
AA x8
FXAA Ultra
ATOC All trees and grass
VSync disabled
Post processing Disabled
HDR Standard
Anisotropic filtering ULTRA
PIP High
Dynamic Light Ultra
Single player
40-70 fps
Multiplayer 25-50