So, recently got crysis 3. Game runs fine [40-50 fps] but when im sprinting through the more open maps [pretty much exclusively the long grass ones] i get massive FPS drops [down to like 10-11]

My graphics card is a MSI-Nvidia GTX 680, so that shouldnt be the problem.

My CPU is an old Intel Dual core OCed to 3.8ghz.. but im thinking the duel core is bottlenecking my system and slowing me down..

Thoughts?

Yes, your CPU is such a bottleneck for your 680 and it's holding it back. Get an i5/ i7(or AMD equivalent) as soon as possible.

Actually just going from my e8500 at 4.4ghz to a q6600 at 3.6ghz net me an additional 30+fps with my gtx 560 ti. If you're tight on cash q6600 overclock stupid well if you get the slacr version and can be had on ebay for about 60 bucks.