im using a GeForceFX5200 256mb but the card your running (my old card) is actually better i only got this cause mine broke

the best value card out there right now would have to be the GeForce6600 if you can stretch that far - If not go for ATLEAST a fx5700 otherwise you wont notice the differance. . . . i wont comment on ATi cards cause i have never used, plus there drivers have issues with *some* games