Originally Posted by Some_Idiot2
Really? They both have the same amount of pixel pipelines, but the SLI GS setup has 2 more vertexes, and they both have the same amount of memory (2x256=512).
Sorry but it doesn't work like that. you get 1/2 your screen using a 256MB 6800 performance and the other half using 256MB 6800 performance. Not the whole at 512MB 6800 performance. Think of it like, 2 identical trucks. The top speed of each truck would not change reguardless if they were together or not. But when you get them pulling a load, 2 pull much better than one. They are the 6800's. Compared to a bigger and faster and more powerfull truck, the 7800. The 7800 would be able to pull the load faster but would strain more to do so.
A game which requires 512MB GPU power will struggle under 2x256MB. But a game requiring 256 GPU power purrs. Likewise the 512MB will run with the 7800 but would not be able to pump out the same FPS of the 2 6800's in a 256MB situation.
Hope that helps.