Right, lots of fud in this thread.
To clear it down some, regardless of what the benches, results from 3 years ago etc say, WoW is NOWADAYS, pretty hefty on the system, regardless of how it looks. Dalaran and raids are amongst the most demanding areas in the game, often quartering your framerate over the old cities like Ironforge.
This is NOT because it looks amazing, but because the engine the game is built around is ancient in terms of design, and has to brute force a lot of things that modern engines have either optimised, or load share with the GPU.
The xbit review unfortunately is relatively useless because it doesnt tell you where those scores are taken, performance varies massively in WoW dependant on your system and location.
WoW IS massively CPU limited. I have seen the game scale unilaterily more with CPU upgrades (IPC/Clock speed increases the most rather than cores) than GPU upgrades, although with increases in textures, shadowing, lighting and view distance, the game is much heftier on the GPU than it used to be also.
The game is ALSO largely based 1/2 cores, to see how heavily CPU based the game is, load up task manager, change to the performance tab then load the game and go to dalaran, walk around for 20 seconds, then tab out.
You will likely notice the graphs show heavy load on at least the primary core, and likely the second core. I have seen it mentioned that WoW also to some extent seems to throttle on some systems, so as not to completely max CPU, but either way, the usage and dependancy is high.
In your case it IS possible your unbranded/unknown PSU is not quite as up to the task as you hope, there is a vast amount of difference between a good brand 500W and a poor brand 500w.
So a shorter answer to your question.
1. Try to overclock your processor
2. Make sure your have uninstalled all traces of the Nvidia graphics card drivers
3. Check your PSU.
4. If you cant overclock your CPU, consider upgrading to an I5 etc.
The simple fact as I remember you saying, that dropping shadows from max to min did NOT change your framerate virtually guarantees this is either a system performance issue, or a CPU bottleneck, because the new shadowing system on max shadow settings is about 2-3x more demanding than the lower shadow settings.
Given the game and how demanding/how unoptimised it can be, hoping for 1920x1200 maxed settings in Dalaran (one of the most demanding locations in the game) at over 40fps, with your system, to put it mildly might be a little overoptimistic.
