I have 2 systems. The one in the sig and then one just like it only the CPU is an AMD 6000+ @ 3.2ghz and my roommate uses that most of the time. I run my game @ all medium settings and 1680x1050. He runs the game @ 1280x1024 and all medium settings. My average frames while outside are ~30 fps and inside are ~ 60fps. His outside frames average ~20 fps outside and the same ~60 fps inside. Now 10 fps does not seem like alot of difference...I realize this, but when it is the difference between 20 and 30 fps I is a pretty big increase. I was going to try and find some actual CPU benchmark comparisons between AMD and Intel, but I couldnt. So I just did this little evaluation to see if it would help you out. There may be other factors included as we obviously use different motherboards and the systems are not exactly the same, but the core parts are. Hard Drive, Gfx Card, Memory and Numerical CPU Speed. So that is the best I can do.
IMO Crysis is bottlenecked by everything right now, but an Intel CPU will give you a decent % better, but I suppose most people already knew that as the CPU's are on average somewhere around what ~30% faster clock for clock or so. IDK...I thought this may help. I think you may just have your settings slightly to high. I mean if I were you...lol, and I probably will be after x-mas as I am getting the same card lol, I would just run the system on 1680x1050 res or below with no AA and settings on just high with possibly the shaders on medium. Or 1920x1200 res with all medium settings and no AA.
Some settings like that would be more ideal imo for your system...(mine as well...im not bashing your system.) Those we just some suggestions...im not trying to bash AMD or praise Intel here...as most here know and I have just mentioned above I own an AMD system as well, and have had many in the past. Just tryin to help!
Edit: I must note that the AMD system does not pass orthos over 24+ hours, which is what I require to consider it stable, but my roommate does not care (He just likes the number). The cpu can make it somewhere around 6 - 8 hours on the test. This might be affecting the overall performance.
Best,
3Ball