Once i get my mobo back from asus i will be installing my 2 gtx 670 4 gb gpu cards. I have an opption for a trade with a friend that has a GTX 690. Will 2 gtx 670 4gb gpu cards run as well as the gtx 690 4gb? what are the differences between these 2? Would they be the same? Or will the 2 GTX 670 cards be slightly better? or the exact opposite, will the GTX 690 be a better suiter for the gaming experience? Any information is appreciated. Thank you Toms.