Originally Posted by
sonmoris
Firstly, I don't take credits for this, found this on WoW forums and decided to share.
Some of you must have noticed the lower FPS number since 2.3 came out. The solution for this is opening Windows Media Player before starting up WoW.
Computer saves some % of CPU time for background applications. Having the WMP running in background changes the thing - it allows all the remaining CPU time to be used by WoW therefore increasing its permormance.
Works fine for most of people i've spoken with.