I use to have that issue...until I went to 16bit...now I do not have FPS issues.
------------------ "Listen up you stinking maggots. It seems you just don't get it. Well, I've been appointed to inform ya', your days are numbered. You would cry, you would scream if you knew half the things I've seen. Please please just do as I say. Repent and leave your evil ways." - Clutch VISIT GF CLAN SITE EDITED FOR COWARDS
In Omaha, in the worst parts, my fps is around 11-15. In the snowy forest, almost the same. It's those trees and their leaves: they take a lot of processing. My system is old: P3-733MHz, 250MB RAM, Voodoo3 3000, WinXP.
My settings are all in medium. All the advanced and video options are ticked, except compression of textures that is not supported by my Voodoo, shadows are simple, color are 16 bits but textures are 32 bits. Res 800x600. During the game, there were two or three parts that I had to lower the settings and the resolution to 640x480 to be able to play in an more acceptable way.
All I can say is damn. On Omaha(and the rest of the game for that matter) I get anywhere from 35-95 FPS, but on the snowy forest level, all I can get is like 15. Damn!