4 Gig's you mean?
This computer im using now has the Asus M2N-MX-SE PLUS mobo, and I used to have a 9800GT with 4Gig ram.(still have this in it, g.skill) works like a charm, It has a PCI-E 16x slot, can't remember if its 2.0 or 1.0, but etheir way, apart from my droning on it should work fine.
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It will work fine on the M2N-MX-SE plus, I haven't seen the gigabyte bored, but I think its a good assumption seeing as that motherboard chipset isn't too old, and should have PCI-E 2.0 atleast, and 2 DIMM slots for the ram.