Did some research again and following few lines of text is a result of it.
To make WoW work better, the following lines got to be added in your config.wtf file located in WTF directory of your WoW instalation.
SET gxApi "d3d9ex" - Feature to the D3D graphic engine that will come fully in MOP, to improve texture management.
SET processAffinityMask "value" - This allows you to tell WoW how many processor cores your computer has and it will do its best to utilize them.
The "value" should be as follows:
If you are running a single core processor, set this to 1 (sorry but you won't get any performance from this)
If you are running a dual (2) core processor, set this to 3
If you are running a triple (3) core processor, set this to 7
If you are running a quad (4) core processor, set this to 15
If you are running an 8 core processor, set this to 255.
Example: SET processAffinityMask "3"
SET gxTextureCacheSize "value" - You can tell WoW how much memory should/can it use for textures in game instead of just letting WoW to decide.
I've tested it and you can easy put all of your card memory to WoW for best effect (assuming you're not doing something graphically intensive in the background), others say it's safer to give it a half or 3/4 of it though, and should be enough as well I suppose. Anyway it's for sure better to set it then leave it on auto.
The "value" should be as follows:
If you have a 128mb card, set this to 128.
If you have a 256MB video card, set this to 256.
If you have a 512MB video card, set this to 512.
If you have a 896MB video card, set this to 896.
If you have a 1GB video card, set this to 1024.
Example: SET gxTextureCacheSize "1024"
Important: This option only workd with d3dex enabled
Following are optional settings, to be tested by yourselves what suits you best.
SET M2Faster "value" - Values can be between 0 - 3 (1 is default).
M2Faster changes the way our 3D model drawing engine approaches the task of drawing the scene, basically drawing objects in a more optimized order.
M2Faster can improve performance in crowded scenes when "Vertex Animation Shaders" is turned on. This function can be turned off by setting M2Faster to "0" in the config.wtf.
Reduces the unique number of vertex shader permutations that we will choose to use in rendering
Sorts the drawing of items in the scene a little differently to reduce the number of times we re-program the vertex shader hardware.
I've read a lot and seems with todays high end PC's it's best to set it to "3" for best effect, but it's individual PC configuration dependent.
SET timingMethod "value" - Values can be between 0 - 2 (0 as disabled/default)
This one is interesting.
"You can significantly speed up WoW on Windows with a simple setting. Awhile ago a number of people figured out that if you run windows media player at the same time, the game runs faster! Unbelievable as this sounds, it’s true. And it is because media player tells Windows to use different timings which can be better for WoW. This works especially well on older or multi-core computers but seems to help just about anyone if only just a little. You may see your load times go down and your frames per second go up.
Media Player essentially changes your thread scheduler timings using a windows API. This effects every program running on your computer. This tweak is fairly well known in other games and among server admins, but it was just discovered or rediscovered to work for WoW.
If you don’t care to run media player, or want to have all your computer resources available for WoW. You can directly configure WoW to act similarly using a special command.
Go to your chatline in the game and type either of these commands. Then, restart your game.