I have an older Phenom 9100e processor. I have always wondered why my FPS is so low; I bought a nice graphics card recently and updated my RAM. Long story short there was an update deployed to fix a bug in the Phenoms that causes massive CPU bottlenecking, negatively affecting WoW's/other game's performance. In turn, the update fixed a bug at the cost of CPU performance. Disabling this fix drastically increased my FPS.
I have tried many things to increase my FPS, and this is the ONLY THING that has ever worked.
Basically if you run Vista/7 and you have a phenom QUAD-CORE processor, read this:
http://www.hardwarecanucks.com/forum...ur-phenom.html
Scroll down to the "With full credit to Sam2008 the following instructions are how to dig yourself out of the mire.
Programs to download:" to skip all the explanation.
Make sure you set the task scheduler to run the program every time you start up. You can literally enable the fix again mid-game to see the FPS-loss, then re-enable it.
Happy gaming