Originally Posted by Polymerabbit
For $400 you could build a pretty decent replacement if you reuse the case.
Get something like this:
-Phenom II x4 955
An Athlon 64 in this day and age is severely outdated, and will bottleneck any good GPU.
Its not as bad as you'd think, but its nothing impressive. I have a spare pc next to my current one, basically dedicated for gaming at 1280x1024, and I pretty much max out source engine games with it. Not bad for a 4600+ and a 5670. Upgrading would show a huge increase though. Definitely look at getting a mobo+cpu combo from a microcenter if you have one near you. They're amazingly inexpensive for the price. A friend of minegot a Phenom II x4 840 & a Msi board with Mosfet cooling
for ~108 bucks at a microcenter. He ended up building a pc for ~350 bucks which can play most games these days.