Drivers and their low gpu usage.  If you monitor it with a program like Afterburner or Precision so you can see it in game, WoW is one of those wonderful, 25~45% GPU usage games for us.

WoW does not play nice with SLI, try overclocking your cpu, its more CPU and HDD intensive than anything, on my GTX480 its >100fps everywhere but main cities and 25m raids where its 40-70fps (game is coded to only use 2 cores and my cpu is maxed on 2 cores)

HippieMagic

You have to make the game run in DirectX 11 mode in the advanced settings under the graphics settings.  You need to check it after you set it to DX11 because it may revert back to DX9.  If it keeps reverting back to DX9 you have to delete your W T F folder and try it again.  This should fix the issue.  DX11 should be a noticeable increase in performance. Keep in mind you have to exit and restart the game to see.

Water, a lot of fire, a lot of people, a lot of casting... all that could drop you into the 40s-70s easily.  I have hit the 40s on SLI GTX580s due to Orgrimmar a few times and tend to run BGs at 70 and up depending.

Questing is anywhere between 140-260fps on ultra everything 16x AA and 8x MS. 

If you want to get more FPS lower your shadow detail and turn off sunshafts.  My FPS values are with everything turned up to max.

 
That's because you have low GPU usage as well.  Most titles give you better frame rate in DX9, not DX11, and neither DX9 nor DX11 for WoW enable a high % of GPU usage.
 
The most OP can do after the basic tricks is go into his SLI profile for WoW, in nVidia Inspector, and start editing the Bits.  This usually doesn't fix anything and causes more problems, but it can be worth a try.
 
RC

This is what the OP tried:
 
Things Ive tried. 
Disabled HT on the I7 
Set Preferred Performance in the Nvidia Program Profile 
Individually decreased every graphic setting in the game attempting to find a culprit.  No changes. 
Tried DX 9 and DX 11 
Reinstalled Windows.  Did a clean reinstall of WoW 
Tried latest 275.33 Drivers.  Rolled back to 270.61.  No difference in performance. 
Disabled Multi GPU 
 
The only time DX11 makes a huge difference in performance is when one has perhaps a CPU Bottleneck, with a powerful GPU installed, what it does is put more work load on the GPU as opposed the CPU.  There is no bottleneck in the OP's situation.  Assuming if he has OC its adequately voltaged and stable, not artificially limiting his own performance.
 
Disabling Addons is not the solution, with the exception of a problematic one that interferes with WoW's operation.
 
I have had both SLI 580 and SLI 590s, there is extremely low GPU usage by both DX9 and DX11.  There are also a ton of titles that also exhibit this behavior, such as Dragon Age 2, or Shift 2.  The performance can get abysmally low.
 
The OP's rig is more than sufficient to run World of Warcraft, it is poor in game coding, poor driver support, or both.  If you monitor your GPU usage, you would see that your GPU usage fluctuates unbearably bad, between 25% to a whopping high of 45%, sometimes you can get better performance from a single card, leading me to think its a lack of SLI polish, but many 4xx/5xx users also experience it in a single card configuration.  More likely leading to drivers, since it is such a multi-title issue.
 
I don't mean to argue, but WoW is not the only case of this.
 
I also know I am going against the grain on this, nVidia's drivers are usually more superior to ATI/AMD, especially in the past.  While I stick think Team RED sucks when it comes to support/drivers, nVidia have not been doing so good themselves. 

The wow Dx11 patch was nothing aesthetically it was done t improve performance.  If you google it most high end systems see a 30% fps increase in dx11 mode in wow.

Thanks for all the quick replies fellas.
I tried forcing Alternate frame rendering 2 and still nothing improved.
Whats boggling my mind is that others using single 500 and 400 series cards are experiencing better performance in WoW than I am.  Like I said before, even my Xfired 5870's didn't down like this.
 
Ive ran it in single GPU mode and no improvement.

I know my card has had issues in SLI with games like crysis and fear pm. I would get half of the frames then what I would in single gpu mode. The gtx590 has its quirks sadly.

Shadow effects and sunshafts drop my fps around 10-20.  It isn't a HORRIBLE drop but it definitely isn't great.
 
I would go into an empty field by yourself to see just how your performance is.  If you are running ultra you just won't see 100+ fps in a raid.  You most likely won't even see 100 in orgrimmar or stormwind... it will probably be between 30-80 in those scenarios and it MAY seem choppy.  WoW has been improved lately but it is still a really old game so it does have quirks.

RainStryke

Try this:
Expand a shortcut to the woW.exe with "-d3d11". Alternatively, open the "Config.****" in "\ World of Warcraft \ Beta \ ****" and add the line SET gxApi "d3d11" (with quotes)

Source:
http://www.bit-tech.net/news/gaming/2010/07/06/wow-cataclysm-dabbles-in-dx11/1

Since the forum does not allow "W T F" it's ****'d out. It's the 4th sentence down.

as of cata you dont need to do this as they added in game gui to turn this on and off.

wrinvert

RainStryke

Try this:
Expand a shortcut to the woW.exe with "-d3d11". Alternatively, open the "Config.****" in "\ World of Warcraft \ Beta \ ****" and add the line SET gxApi "d3d11" (with quotes)

Source:
http://www.bit-tech.net/news/gaming/2010/07/06/wow-cataclysm-dabbles-in-dx11/1

Since the forum does not allow "W T F" it's ****'d out. It's the 4th sentence down.

as of cata you dont need to do this as they added in game gui to turn this on and off.

 
Yes, but this has worked as a fix before. Might want to give it a try.

Well, there is a hack you can put into your config file to get full thread usage, I had to do it for mine since moving to Sb. Also I've found useing shadows at only half helps a lot because the game doesn't render a lot of things correctly with full shadows on. There's also a bunch of really bad add-ons that have mem leaks and other problems that will just destroy your fps. We really need the op to comeback and tell us if he's overclocking his CPU, what clock its at? We really need to know what add ons he's useing too. I'm on my phone rite now but I will comeback and post the link for how to enable all threads.

Again, I want to add that NONE of the suggested fixes are going to work with the 590.  You're better off just selling it if you're an avid WoW player.
 
I went back to the 580 GTX w/ 3 Gigs of RAM and I'm seeing much higher FPS then I EVER did with the 590; running single core, building custom SLi profiles, etc.
 
 
Blizzard, will adamantly ignore any tech questions regarding the card as well.
 

mrchacko

Again, I want to add that NONE of the suggested fixes are going to work with the 590.  You're better off just selling it if you're an avid WoW player.

I went back to the 580 GTX w/ 3 Gigs of RAM and I'm seeing much higher FPS then I EVER did with the 590; running single core, building custom SLi profiles, etc.


Blizzard, will adamantly ignore any tech questions regarding the card as well.

+1 hence the reason i bought a 580HC2 instead of a 590. (no 3gb at the time and the HC2 was the fastest out of the box card)
note: wow only uses about 800-900 megs of vram w/ everything maxed on 1920x1080.

First, 266.58 are the best drivers to use on a 590 and WoW.  No idea the technical reasons why, but this has been tested by me and seems to be true each time I try (seems to average about 10-15 fps difference).
 
I would like to give some advice on how I get these to run smooth but it really comes down to trial and error with the 590 and WoW.  Some people it runs great right out the starting gate others I've spent literally hours messing with the settings getting it to like normal play and raid play.
 
Anyways, good luck.  I can tell you that when people ask me for suggestions of video cards and they bring up WoW as major game of choice I will lead them away from 590s most of the time.  Usually sli'd 570/580s dependent on money/availability.

When setting the program file in the Nvidia control panel.  The setting "Multi-GPU rendering mode".  If set to single GPU, will that effectively run the game in single GPU mode, or is it a better route to disable multi GPU under multi GPU configuration and restart?