Is it worth upgrading from 2 Geforce 7950GX2 in Quad SLI to a Geforce GTX580?

My old Athlon64 system died, so I just built a i5 sandy bridge system almost from the ground up. I thought I could get away with keeping the old and Video cards which are XFX Geforce 7950GX2, but the performance in newer games such as The Witcher 2 and Duke Nukem Forever is below 25FPS on medium graphical settings at 1280X720.



Alternatively I was thinking maybe two(2) Geforce GTX560-TIs in SLI would offer good performance if SLI has gotten any better from 2006.|||SLI improved with the Fermi series. Sometimes you will see a 50%-80% improvment by adding a second GTX 400/500 series card in SLI. With the GTX 200 series cards in SLI you would see a 50% performance gain at the most.



As you know, it all depends on the game.



Just two of the regular GTX 560 (non-ti) cards in SLI are a little bit more powerful than a single GTX 580. Two of the GTX 560 ti cards in SLI are almost as powerful as a Single GTX 590 Dual-GPU card.



The GTX 580 is a very nice card but it just doesn't give you much bang for your buck. The GTX 580 is 12% faster than the GTX 570 but the GTX 580 costs 42% more than the GTX 570.



Single cards like the GTX 560 ti and the Radeon 6950 will play most games on the highest settings using a 1080p monitor.|||Upgrading to a GTX260 would be a upgrade from the 7950GX2 which is several generations older then the GTX580

So really asking if it's worth it is a dumb question

But since you're running such a low res using a 580 would be a waste of a good video card|||2 560's would be awesome, but keep in mind a 570GTX would cost $150 less. Your only hold back with the 570GTX is you will need a PSU with 38+Amps on the +12Volt rail of your PSU. So if you already had a good enough spec PSU the 570GTX overclocked would be your better value. Especially since you aren't using high resolution.