Well of course it runs FEAR slow. A 6600GT is a small budget card, so the best settings to run games on it, is probably low at best. Maybe medium sometimes.
I have a 6600GT PCi-E and I can run F.E.A.R @ an average frame rate of 50-60 fps @ 1024x786 with max to med setting and soft shadows tunred ON and Antialiasing : 4x and FSAA x16.
I must add my 6600GT is OC'ed to 575mhz core and 1300mhz for the mem. STD setting are 500/1000.