hmm......i dunno of 512MB of ram is enough dude. get 2GB Dual Channel Ram. buy the Opteron 165 or the X2 3800+ and as for video card, either get a 7900GT or a x1800 XT, because u dont want to spend a large amount of money on a G80 after ur spent over $500 for a 7900GTX. get a GT or x1800 XT, then save up for a G80 or maybe even a R600 ( but those are a while away, way away). 4600 and 4200 have low cache so they are bad altogether.