I want to convert my rather large DVD collection to .avi files using Gordian Knot and the Xvid codec. I decided to build a new rig to do this. My question is which would do this quicker: a system built around an E8400 or a dual processor server setup using 2 - Opteron 2212 processors?

Just go with a quad core processor, such as the q6600. You do not need a server to rip .avi files. The e8400 will work as well, but a quad core would be much faster at ripping files. Since the e8400 and the q6600 cost roughly the same I would just get the q6600.

I thougt a quad core would be better too, but looking at Tom's CPU charts, it looks like the 8400 would beat out the quads in Xvid conversion.