having a seperate machine server the SQL would speed up the server on a whole?

It is probably save to say that overall MySQL 5 is not faster or slower that previous versions. At work we have like 20 MySQL 4.1 and 6 5.0 installations on comparable hardware. The only reason we are using 5.0 is because of needed new features.

What I meant was that if you use dedicated machines for dedicated tasks you can spread the workload over more than one machine.

Instead of burdening one machine with both the MySQL server and EQEmu zones you could use multiple machines, one for the server and one or more for EQEmu zones.

Yes, dedicated hardware for difference network services is always the best idea. When a zone loads, it tasks the CPU. When it loads it also fetches data from SQL, which also tasks the CPU. If you have any other tasks going on (LSASS, CSRSS, cidaemon, backup software, blah blah), you're going to see CPU spikes of 100%. Naturally, if there's no CPU left, it slows everything down.

That said, I have not seen the Emu gobble up enough resources to be a problem (except when I code horribly wrong and cause race conditions that eat the machine alive). Best scenario? 1 PC for world/zones. 1 PC for SQL. 1 PC to play from (you). Anything else i am missing?

(perl lives on the World box - if it's even necessary anymore?)