Time to explore the synthetic side of things. This is only interesting for the benchers amongst us. Though can still give a good indication of real world performance. First up Futuremarks 3DMark06.
Both the GTX560 cards nicely outperforming the stock clocked GTX 460 1Gb card. The difference between the reference GTX560 Ti and the MSI OC'ed version seems small, though 400 points extra is a nice gain. Looking at the SLI result, we are running out of CPU power here, 4Ghz is not cutting it in this benchmark. Time to move to a heavier GPU dependant benchmark : 3DMark Vantage.
This benchmark reflects in a similar way the game test results. GTX 560 Ti cards thrashing the GTX460 card. And in SLI mode even obliterating a GTX 580 card. With more CPU speed the difference would be even more noticeable.
HWbot has created together with the nice folks at unigene a real GPU benchmark. You can run this benchmark at 4 or 6Ghz CPU clocks, it won't matter much for the end result as it's the heaviest GPU synthetic test. If it can pass Unigene at a certain clock speed, it probably will run through all of Futuremarks tests without any major issues. Don't be fooled by the little performance differences. A 100 point increase is already a big increase in the Unigene test. The overclocked card keeping nicely ahead of the 560 Ti with reference clocks. The 1432 score of the GTX580 is no competition for the 2000 point score when you bundle the power of two of these little 560 Ti cards.