On the 7xx series: Oh, woe to my 580gtx SLI rig...

[False Christian]

I love SLI. Generally you get about 80% more performance in SLI over just 1 card.

I have 2 eVGA GTX 760 4GB using just a 22" 1680x1050 LCD monitor and I'm getting over twice the frame-rates as my old 2 eVGA GTX 460 1GB SLI setup.

 

[Starrbuck]

780 all the way