i just upgraded from a intel p4 2.4C @ 2.95Ghz, 2GB of DDR-500 ram, 6600GT to an amd opteron 170, asus a8n32-sli, and a 8800GTS 320MB for 600 bucks. hopefully i should see some increase...its my first upgrade in years!!!
of course i looked at going the core 2 route, but its too expensive (i have to add ram, and the mobos get expensive - at least the one i want). this way, i reuse everything except the cpu, mobo, and video card. this should last me for another 4 years.
i sure hope i can at least play crysis...