I have Nvidia GTX 570 , Intel Core I7 2600K 3.7GHZ , 8GB Corsair Vengeance CL8 1600mhz @ 1680x1050 in begening of game was around 40 Fps on Ultra with DX11 enabled but than im getting around 30 Fps or low..
and my ping is not high! its 93-110.
crysis 2 with the dx11 patch installed is a very graphics intense game...my 480sli setup can't keep up with it at times....then again i have everything on ultra settings and i play at 1920x1200 resolution....it only dips below 35fps when i use grenades and there is a lot of stuff going on...other than that i usually get 45+fps
contrary to what anyone says about crysis 2,it was actually a very demanding game right from the start though not as much as crysis 1.At max settings with object detail at very high I get the same fps that I get in crysis 1 on near max.
The multi player component is more demanding than the single player.I will tell you the maps which you are lagging in.One is city hall,the second is lighthouse and pier 17.These levels destroy nearly every card out there at max.My suggestion is lower the object detail to very high.You will gaing 10 fps and even if its the medium setting,trust me there is NO POP IN whatsoever
Crysis 2 with the DX11 ultra patch and hi-res texture patch is extremely demanding. It doesn't sound like your FPS is out of the norm. A good SLI or X-Fire setup is required to get anywhere near the 60 fps mark with everything maxed. I'm running 2 Radeon HD6950's and max it all at 1080p res, and even I drop down to 35fps on the odd occasion.