the processor is definitely the problem if you're not happy, 660ti is fine for most games on 1080p ultra, with msaa off.
get the fx 8320 and overclock it. If you don't want to overclock, which I understand people don't like to mess with that stuff sometimes, the 8350 is fine and on par with the i5 in many games, although i5 does beat it in cpu intensive games.
even the 6300 would be an improvement because it's piledriver as well