The only system I have.

2.8 Gz Pentium 4, 1 Gig RAM, GeForce 4400.

I'm very impressed with the performace. I figured my processor and memory would be up to the task but my video card is rather old. But I've been running with on high resolution with a lot of details turned on, and the only time I've noticed a slowdown was when a building collapsed and filled the air with dust. Other than that, it's been great.