In crysis 3 it's recommended going with a quad core cpu :
http://www.techspot.com/articles-info/642/bench/CPU_03.png
"Looking at the performance of various processors and platforms, it's safe to say you'll want to play Crysis 3 with a quad-core processor"
If your getting the same fps in every resolution, it's the cpu that's bottlenecking it(in that particular game).
Also worth mention crysis is a really demanding game in both cpu and gpu parts.