I am currently running 1 gig(512x2) in my msi 865 motherboard with a 7600gt agp. Im looking to move up to 2 gig. I have 4 slots with 2 empty right now. Is there any reason I shouldnt just get the other 2 512 sticks for the empty slots. I plan to buy the same brand/make I currently have(corsair) so all 4 sticks match. Or would I be better off spending the extra money for 2 one gig sticks.