There is always a bottleneck somewhere, 660 would still find opportunites to perform better if we had the same systems side by side with both cards/same settings, overall benchmarks would have higher min/average fps on the 660. Could you find CPU or GPU bottlenecks if settings are too high? Of course, you have to it down if it's not smooth. Still don't believe me put a slower card in your older computer and run the same benchmarks.