What CPU do you have? What res were you running?
I have a GeForce2 Ultra card and the FR is great with all settings maxed out and 1024x768 res. This is with an Athlon 1.4GHz.
Processor makes a difference. Also, don't get caught up into trying to run a super high resolution. Once you get past 1024x768, it doesn't make *that* much difference in image quality, IMHO, but the framerate definitely takes a hit.