Without knowing what kind of motherboard you have, it's hard to say..
Most motherboards a few years old will have an AGP port (which is better than PCI).. however, if you can.. getting a PCI-E card is even better..
Yeah, all these PCI's flying everywhere
Just make sure to get the one with the "E" at the end (if your system allows it)...
Can you post your system... or at least the mobo you have? We might be able to better answer your question
ALSO, we have a new forum just for stuff like this
Might want to try your question there (or let us know and we can transfer it over there)..