Re: GTX 660 not performing to full potential?
Relatively old post, but I just want to note that the 549 GPU clock speed does suggest a problem (much lower than the 660's maximum clock speed), perhaps with powermizer. Older cards have an option to prefer the maximum performance level, not sure if the Kepler cards have this option.
Additionally, the performance of a 570 and 660 should be relatively similar, which isn't really that surprising. First number = generation, second number = performance level. Anyways, I bought a 660 myself so I guess I'll be posting back here if I have the same performance issues when it arrives.