it wont come o/ced from nvidia but possibly the manufacturer will o/c it some.
as has been said Riva Tuner is very good and worth looking into for advanced tweaking but coolbits is much easier to use , adds everything to your nvidia control panel.
I used a Zalman cooler on my old 6800Ultra it was very good , however its quite deep so i dont know if they would be anygood for sli rigs but its worth checking out.
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