You said:
WoW loves high CPU clockspeeds, you wont gain much FPS in WoW with a standard i5, you need an overclockable one to see real gains (which needs a motherboard that supports this).
In fact most games dont require more than 2 cores, and even when they can leverage more than 2 cores an i3 again is similar to an i5 in that it has hyperthreading which is two virtual cores which many games can take advantage of.
My recommendations above stand, remove the PSU if you dont need it.
I think whats happening here is you think your CPU isnt good enough, but it is. Most games run almost as well on an i3 an i7, here is a fairly recent game benchmark with your exact CPU against others that cost wayyy more:
http://www.tomshardware.com/reviews/...ce,3996-4.html
Some games like more cores, some games like higher clockspeeds. But in general most games play similarly no matter what CPU is in your system, this is only going to be more true going forward with the invent of dx12.