I play it on max settings on my macbook, 2.3ghz i7, 8gb ram, 1gb Radeon 6750M. So you'll have no problems I reckon, game looks beautiful on medium settings anyhoo.
You should be fine. I'm on an i5-3570K @ 3.4GHz (stock) with a GTX670ti and 16GB of RAM but I gave the second copy I got to my son and and it's perfectly playable on my kid's old Q6600 quad core rig with only 8GB of RAM. I have my settings maxed out; didn't check them on his but the game looked good.