What settings will give me the best performance on my hardware

[darthxaos]

Windows 7
Intel(R) Core(TM) i3-2120 CPU @ 3.30GHz (4 CPUs), ~3.3GHz
8G RAM
Radeon HD 6850 with 1GB GDDR5

What settings should I choose for by graphic options, render quality, etc, also, should I change any settings in Catalyst Control?

[Ailos]

I wouldn't worry about having to turn down render quality or anything of the sort. Sticking the graphics to the game's medium default should give you a quite smooth experience, and you may even be able to use high.

[Rbstr]

Best performance?

Everything on lowest possible.

[Lee]

As long as you are cpu bound, you can try to increase the graphic details, you might be able to go from low to medium, or from medium to high and keep the same framerate. When your graphic card becomes the bottleneck, you stop increasing the graphics, and try to find a sweetspot.