Single machine 10-boxing survey/speculation

[Bollwerk]

Would probably see better performance if you switched to Intel.
If you could afford it, maybe even go with a 2 socket MB and get a pair of quad core i7 procs.

Intel > AMD for WoW Cataclysm

But if you want to save money, I'd suggest using some of your old machines to run some slaves.

Also hope you're using Windows 7, since you have an SSD.