Spoken

Speeding up MySQL on Mac OS X and Mac OS X server: Basically: you want to add “skip-thread-priority” to your my.conf, or use “–skip-thread-priority” when you start up MySQL on an OS X box. There’s an assumption about how thread priorities are ordered which isn’t true on OS X. By turning this off, you can significantly improve your overall database performance. On some of my databases, I’ve been able to double the queries-per-second just by setting this value. [Cool.]
Source: Chuqui