[theedisoneffect]

Forget the 7800gs, the 2.4ghz P4 will bottleneck it, so you won't really see much or any gain over a cheaper card.

Honestly, you might be just as well off with something like this:

http://www.newegg.com/Product/Produc...82E16814141038

It still performs pretty well, maybe not quite up to a x1650xt, but still pretty decent and it's quite a bit cheaper.