Radeon 4850, fraps, crysis question...

Alright im wanting to test my new card, which is a radeon 4850 1gig, and im wanting to know how much fraps reduces frame rates and if the framerates are right for this card? I was playing crysis demo (dont have the game YET!) at 1650 1080 (i think thats right lol) with vhigh settings, no aa and getting 15 to 25 fps. I noticed it seemed a little slower with fraps on so what do you guys think the real fps is? I tried messing with that sandbox thing (to complicated for me) and i noticed a little framerate on the main bar and is said anywhere from 28 to 40 fps and im not sure if that is the same fps im getting in the game without fraps.
Im getting crysis maximum edition (FINALLY) and im wondering if the performance will be better in the game than in the demo of the original crysis.
Ign said warhead runs better and looks better than the original crysis so im exited to see what it looks like! Also which would you rather play on in crysis 1920 1200 everything vhigh exept with shaders on high(which packs the most punch detail wise in crysis) or 1650 1080 with everything vhigh? Ok last question, my rig is a i7 920, 6ram, and 4850 1gig all on a 24in monitor and im wanting to know if those are the right fps i should be getting, keep in mind that it is the demo of crysis not the full game, im hoping the full game runs better because of a patch or something =).
Thanks for any replies!