"Imagery has emerged of a Mars 2 (or II) reference board that fits two 480s on its densely populated surface, and is fed by not one, not two, but three 8-pin auxiliary power connectors." Provided that dual GTX 480 could be brought to market, the performance would likely be more than enough to handle any game that'll be released within next two to three years. The cooling and power supply considerations would be challenging, but it would be more than feasible for any high end system built effectively," stats Engadget.
"When Fermi graphics card from Nvidia, and Galaxy dual GTX 470, was unveiled, general consensus was that it could be too power hungry to support a dual card configuration. In terms of performance, a single GTX 470 is slightly less powerful than dual GTX 275 SLI configuration. Therefore, a dual GTX 470 would easily outperform a dual GTX 275 SLI setup."