GTX 590 Quad sli performance issues in surround

HI guys, I as many people in the past have done built a quad sli computer using 2 EVGA gtx 590 Graphics cards with 3gigs of video ram. I am running this computer on an AS Rock extreme 7 gen 3 lga 1155 Mother Board with a I7 2600K over clocked to 4.6 Gighrtz. I also just purchased 2 more 1080P monitors so I am gaming surround 2d mode.

The performance off this system has been very discouraging. First off when I take one off the cards out the frame rates are much more stable and the GPU usage is more consistantley and higher. Second off, the frame rates in allot of cases is just as high with one card as it is with two.

I have tried re installing drivers and such and none of that seems to work. Oddly enough the newest nvidia drivers 306 and 310 actually cripple the quad sli setup. When using the Render.perfoverlayvisible add-on to Battle field 3 I can see my 2 gtx 590s become the bottleneck when I am using any drivers that are 300 series and up. So I have been forced to revert back to 200 series drivers specifically 290 in order to get the graphics cards usage to go above 45 to 50 percent usage. When I am using the 290 drivers my video cards stay ahead of my CPU and my CPU appears to be a bottleneck, but when viewing the in game CPU usage none of my 8 threads ever goes above 75%, how on earth could it be a bottleneck if it isn't being fully utilized.

I am considering purchasing a asrock extreme 6 motherboard and an I7 3930K CPU because I have heard from some that the 2600K 16 pci lanes could be the limiting factor, but unfortuantley I cant find any benchmarks or people through forums that have discussed this choice in detail. Do You think that upgrading to the 3930K which has 40 pci express lanes vrs 2600K 16 would make any difference to my quad sli setup, or does nvida just suck and they no longer support quad sli drivers in their new drivers. Has anyone dealt with poor performance from quad sli in surround mode and figured it out or is it an unsolvable issue?

Any help would be appreciated.