I must confess the SLI is a really cool technology. I assembled a SLI station based on the new nVidia Geforce 7600 GS series. This is a little graphic card compared to the high-end ones like the 7900GTX or the big monster 7950 GX2 (which in passing is really quiet in spite of its two GPUs and ventirads): the price of a 7600GS is about 100 euros, the price of a 7900GTX is about 400 euros and the cost of the 7950 GX2 climbs up to 500 euros! In terms of shader pipelines, the 7600 GS has 5 vertex pipes and 12 pixel pipes, the 7900 GTX has 8 vertex pipes / 24 pixel pipes and the GX2 has 48 pixel pipes and 16 vertex pipes. And so what? A 7600 GS SLI system offers almost the same level of gpu power than a 7800/7900 for a half price. I’ve verified this fact with the latest version of the soft shadows benchmark. With one 7600 GS (single GPU mode) the score is 510 o3Marks. With the two 7600 GS in SLI mode, the score jumps to 1004 o3Marks. The 7950 GX2’s score in single GPU is about 1200 o3Marks. Ok my bench is a small bench, you’re right. What about 3dmrk06? The 3DMark06 score is 4115 for the 7600 GS SLI system. This score is close to the ones got with a non-overclocked gf7800/7900.
Little remark: my 7600 GS are not overclocked.
Conlusion: for 200 euros you can have an excellent graphic system which is also silent thanks to the 7600GS passive cooler!