First of all, my specs:

-Asrock P4VM900 Motherboard FSB 800

One of those rare boards that unite the old ways (s.478 ) with the new ones (PCI-E x16)

-Pentium 4 3.0GHz hyperthreaded

Prescott core, runs at about 46C with 2700RPM stock cooler at idle

1280MB RAM (1GB+256MB DDR400)

-Gainward bliss 7200GS PCX 128MB 450MHz core 600MHz memory clocked to 500 and 750

Works little better than that integrated one lol

So, here's the thing

If I buy, let's say 8800 gts and stick it in my rig, what would I get?

would I be able to play Crysis or COD 4 at higher settings and get decent framerate, or am I being bottlenecked by my FSB, the older DDR400, or something?