Well i currently try and have my resolution set on 1024 768, i use 2 monitors 1 13 inch TFT and a 12 /11 inch CRT. I have tried to update all my drivers as much as possible and i got games booster and some other utilities off Io-bit they have speeded up my PC, and i also disable Sound on my WOW' s, i think it helps .
One of the best boosts i got was from some Io-bit utility tools it optimizes/configures my internet speed, downloads are like 6 mins for 800mb or something now, although i don't think its much of a wow boost thing.
My wow settings are all on minimal, and lowest res allowed. All boxes which can be checked for performance has been checked.