River Tarnell:
this would make more sense with two MySQL instances on a single server (using separate disks). MySQL itself doesn't use all that much CPU.
i should add that zedler is a four-CPU machine with two sockets populated. it can also take dual-core Opterons, for a total of eight cores if CPU use does become an issue in the future.
(unfortunately though dual-core 8xx CPUs are very expensive.)
- river.