I currently just purchased crysis when it when on sale during the steam summer deal. Originally i was playing with the optimal performance button which changed my setting's to high and my fps was around 30+ but i thought i would turn it down to see if i could get smoother gameplay and even on low i got almost the exact same fps as i did when i was on high. Does that even make sense? I know the game is very rough on GPU's but i would assume my PC could handle it.(I'm using the 64bit launcher tweak since steam doesnt have one for the original crysis.) Im assuming that my HDD might be slowing it down but no idea.
CPU: AMD phenom x4 965
GPU: MSI Twin 560 Ti
RAM: Corsair Vengeance 8GB
PSU: Corsair CMPSU-650TX
HDD: WD Caviar Green 1.5 TB
OS:Windows 7 Home 64bit
Case: CM Storm Scout w/ 3 LED fans (2x140mm and 1x120mm)
Generic CD drive
I play at 1920x1080 resolution.
normally that behavior points to a gpu bottleneck but the 560 is within the limits of the 965 by a margin so unless your running 533 or 667 ram i dont see why your not getting over 30 fps...
make sure you have fsaa turned down. remove the launcher it may be applying settings outside of your control. just use the 32bit exe as theres no real difference. if you want you can apply the large address aware patcher theres a few versions knocking round the web and it does exactly the same as the 64bit but on the 32bit exe which means more stability. laa_2_0_4 is the version i use... just select the exe and check to see if its laa enabled if not make it so. but keep a backup of the original just in case.,
you can use this laa patcher with almost any game. some will work others wont. i used it on skyrim b4 it was patched to laa and a few others.