I have an older system (parts thrown together) for a relative. Running XP, P4 3.0 wanting it to be able to play some older games (UT 2004, Doom 3, etc). Wanting to upgrade from a Geforce 4 4200 to something better. What AGP card can u recommend, was thinking of something like an aTi 9800 or better. At what point will a better card not make much difference?