Sam can consider to have his MYSQL sever running in a separated box apart from the same box hosting Apache & PHP during next upgrade.
That is to setup a new server box within the same data center, running only MYSQL dedicated, link via 1000BT ethernet to the existing box, through standard TCPIP port #3306. Migrate the SQL DB over there from existing box, and point this V-bulletin's PHP over to the new box for database. Once working drop the SQL DB & turn off the MYSQL Server at localhost. From then onwards this box will be only the Apache web & PHP server only. SQL database is in another stronger box with more RAM & CPU power.
This is going to $$$cost$$$ few hundred more per month.
So sell ads space to cover?:p
For a V-Bulletin forum like this, usually Apache is not so big overhead for CPU & RAM (only WAN bandwidth mainly). PHP is slightly more CPU & RAM (heavier on CPU side). MYSQL is the main consumption of RAM & CPU resources in this case. It is not so bad at the beginning when the database is small, when we guys posted more and more and number of user A/C increased, the load expands exponentially upwards on CPU & RAM, taken to do each SQL search & update. I know that Sam got customized scripts to anti-spam and clean up this forum besides the regular V-bulletin PHP scripts, do not under-estimate these things, they can take up more CPU + RAM on the MYSQL side, surely also load down the PHP or whatever script host which Sam's script are written in, I assume it is PHP, but can be Perl or Ruby or anything.