hmm but a gtx 670 is again between 100 and 170 bugs more (depending on which GTX 660-version) ... and like i said before the power is not the big thing.

I am using just a i5-2400 with 3,10 GHz
6GB RAM
and slow SATA harddisks

So i guess a GTX 670 would be more than over the top :-/