GTX 780 in SLI too much for my system?

chronos00

Reputable
Mar 11, 2015
13
0
4,520
So, I recently got a crazy steal on two Galaxy GTX 780 GCs from tiger direct(refurbished, $200 each). I'm wondering a couple of things though. One, do I need to even SLI them to get better performance in the games that I play(BF4, witcher 2, skyrim)? Two, will they be effectively put to use in the system that I have? Currently, I'm running:

core i7 920@3.5 ghz (water cooled)
3x4gb 1333 ram
2 gtx 660 in sli(will be replacing with the 780(s) and selling)
alienware 750w psu

So...do I need to build an entirely different rig to support these cards, or would I be alright with a few modifications, like say a psu with more wattage, or a better cpu for the asus p6t deluxe mb(maybe an i7 970)?....or am I fine as is?