People who assume 4 cores is faster than 2 cores don't know even the basics of computer science.
This game requires 2 cores ( that's what it makes use of. )
My personal computer has a 2.7ghz i5, and it runs beautifully. My laptop has a 2.0ghz i7 and it runs okay ( with a *******r video card, of course. )
I upgraded my video card to a 6950, and my friend took my old video card, an HD 4890, and bought a new i5 @ 3.5ghz. His computer runs the game as well as mine does, if not better. We both run the game at full settings.
This game runs well on relatively low spec computers, looks good and it will run on your friend's CPU assuming a few things: that his ram speed is not too slow, that he has 4GB of ram or more, and that he has a video card that will handle the minimal demands this game makes.