I currently have SLI gtx 560 ti's, 1gb EVGA models. I want more performance and I also built a custom water cooling system, and I thought the GTX 580 hydro copper looked pretty cool since it had the waterblock already on it (And it has 3gb of vram). So, does the 580 stand above the 560 ti SLI by much? Or should I go with the 7970? I feel as if the 560 ti SLI is not as good as a single stronger card, and they don't have very much vram.
Having tried the two solutions back to back on identical rigs I know that the SLi rig is the better performer of the two and in the last couple of years I have only seen a couple of AAA titles that didn't support SLi from the get go and they were Dirt 2 and Alan Wake, both AMD/ATi titles strangely enough.