<p>How do I build a VST plugin on Mac without using Xcode? (I'm using Code::Blocks).</p>

This applies to every application/process, not only mysql. If your database is using 3-20% CPU and the final performance is still unacceptable it means that you don't lack processor power, since it is most of the time idle. What is most probable is your bottleneck is at your HDD or HDD-controller level. Have you tested the I/O bandwitch and access time of your HD?