dude.... you motherboard is limiting the GTX680. GTX 680 is running at PCIE Gen 3 speed or 8GT/s. You are using 2 x16 Gen2 slots. the worst part is that it is only running x8 in dual mode.... I can get to P9200s on 3D MARK easily with ONE GTX 680 along. Better switch to newer broad with Gen 3 support or at least get a board with dual x16 Gen 2. 

jct7236

dude.... you motherboard is limiting the GTX680. GTX 680 is running at PCIE Gen 3 speed or 8GT/s. You are using 2 x16 Gen2 slots. the worst part is that it is only running x8 in dual mode.... I can get to P9200s on 3D MARK easily with ONE GTX 680 along. Better switch to newer broad with Gen 3 support or at least get a board with dual x16 Gen 2. 

 
So a 680 and 580 are pretty much the same thing on pcie 2.0 16x? You need PCI 3.0 to get 3.5 more k on 3dmark? If this is true, im sure tons of people are running the 680 on 2.0 lanes and are super disappointed. But this is good to know... so moral of the story is, if you are going to get a 680 make sure you have PCI 3.0 (unless you want to bottleneck it bad with pcie 2.0) ?

it's not even about PCI-E 2.0 vs PCI-e 3.0, but mostly about the PCI-e lanes pool available on your setup. 680 will not perform right if it is running with 8x lanes and that is what happened when you installed them in SLI (your CPU offers max 16 lanes, each card took 8).
 
you should also get "an upgrade" to PCI-e 3.0 slot once you replace the CPU with Ivy Bridge architecture, but still it will offer only 16 lanes, so your best bet is either upgrade the Motherboard or go with a single GTX 6xx series setup.
 
on the other hand Z68 thanks to NF200 bridge can offer 16x lanes (kinda artificially, not natively) to both cards if they are placed in 2 bottom slots (#3 and #5 according to below picture), but then NF200 will not offer PCI-e 3.0 ever - even with Ivy Bridge CPU (this will become available only to a single primary slot directly connected to CPU).
 

 
EDIT:
I also agree that testing should be re-done with VSYNC turned off for sure, and preferably also against GTX 680 single vs SLI to see the differences for real. one single GTX 680 running at full 16x should be comparable to 570 SLI, I think.

I have the Gigabyte z68-xp-ud3 board with one x16 and one x8 slot. Been kind of disappointed with performance.
 
Looking quickly at Newegg, i see only one x16 x16  68 1155 board: Asus Maximus IV Extreme, for $340, and a p67 1155 board: ASUS p8p67 ws revolution for $270.
 
Would getting either of these make a big performance difference worthy of buying a new board at these prices? TBH I wasn't really looking into buying Ivy Bridge because I hear it's only 2-5% increase over Sandy Bridge. I was really looking forward to Haswell next year.
 
What is my best move?
1) Buying one of these expensive boards, enjoying the "hopefully" decent improvement for my SLI680s.  Buying one of these boards could be now, or waiting for a little longer to see if they drop in price.
 
2) Buying a new x16 x16 PCie 3.0 board when IB comes out, because hopefully these are cheaper then? This option could be either using my 2500k in them (IB is 1155 right?) or also really splurging and getting a miinimal power increase in the IB CPU as well.
3)Making due with what I have, hoping to see some gains with better drivers, though even then, I won't be getting as much out of the cards as I should since I am only on x16 x8 until Haswell/Haswell boards come out next year? This option could also include selling one of the 680s on Ebay.
 
4)Sell both cards on Ebay, looking to buy a single 690. A single 690 in my x16 slot would probably be better than having 680SLI in X16 x8, right? (assuming the 690s arent borderline defective like 590s supposedly were) 
 
When I bought the two 680s I wasn't planning on spending another dime on my computer until Haswell came out. I will buy another mobo prior to that ONLY if the gains are large over x16 x8.
Please help a clueless guy out.
 

Here is my GTX580 Class Ultra's @ 940/2225 same settings on 2D.  Hopefully that is helpful
 

randbfz

According to LinusTechTips, using an 16x SLI setup vs an 8x SLI setup on PCI-E 2.0 is only a 1.0008% increase.

http://www.youtube.com/watch?v=NFMzRZqFh-w

I wouldnt worry about PCI-E 3.0 or 16x SLI anytime soon, as it doesnt seem like there is enough information to push across the PCI bus at this point.  I could be wrong,..

 
The problem I see with that test is it's 3D Mark11 on Extreme which uses about 900MB vram off the top of my head. He is not pushing the bandwidth whatsoever with that test. Trying to quantify it by 1.00008% is absolute nonsense as each test can easily have a variable greater than that.

Hmmm.  Not home yet but I think it may be my SLi bridge after assessing some stuff on it.
 
I'm going to try after I leave the bar from my work shindig tonight.

Ok, so I went BACK to the current WHQL driver, set Physx dedicated to the CPU and switched the SLi bridge cable I had.
 
This was at 5GHz CPU & 1012/2275 on the 580's
 
Does this look more like where it should be at this?  The CPU didn't really make a difference.  The GPU did make a difference, not a ton but it did.
(2D and 3D)

He has so much money tied up in video card processing it is just nutz to have that entry level CPU.