I only have a Athlon 64 X2 6000+ (6gb RAM) and a Geforce GTX 550 Ti (1gb), using the settings such as what Veilo mentioned (although I used to run with shadows/post proc and higher details until a few days ago). Runs pretty well for me considering, but could do with a CPU that wasn't 4 years old
Probably only get 40ish fps, alot less than others I would expect but it does the job for now.