now you can run two instances of your favorite DC program on the same computer, at less than half the speed and twice the cost of a modern platform!
for the average user, two P3 1GHz's is horrible. go for a faster, single CPU solution. if you plan to run a server doing multiple things (a game server running like 10 games at the same time comes to mind) then the two p3's are pretty good. back in the day they used the dual p3's for counter-strike servers and got anywhere from 8-10 ports running off of one computer/ip.
but anyway today dual p3's are outclassed by the athlon-MP line and Xeons and Opterons. if youre looking to play around with smp you can look for p2's or even try to buy someones dual celeron rig.
anyway in summary, for PLAYING games get a FAST single CPU.
edit: changed AXP to AMP