I'll consider the archiving option.
I'm happy to report that I just upgraded tonight to PHP 5.4.9. So I'm now on the latest version of MySQL, the latest version of PHP, and am running FastCGI. I've upgraded to the latest version of UBB. I converted the tables to INNODB. With all those changes, my processor, which used to be pegged solidly at 100%, is now floating at around 50%. Yes it still pegs occasionally but that's fine. The improvement is substantial.
