I went to NVidia.com today and did a Live Chat with their support. I can confirm they acknowledged it's a known issue and said it'll be fixed in upcoming driver releases. No confirmation for the next version of the driver release date or if it'll be fixed in the next release.
Same problem here, 3 ASUS GTX680-DC2-4GD5, ASUS Maximus VI Extreme with i7-4770k CPU.
With 3 cards can enable single monitor 3-way SLI, but Surround can only enable 2-Way SLI. Remove a card and can do 2-way SLI single monitor, can't enable SLI for Surround.
Posting on GeForce.com too...
The release of Ivy Bridge and PCIe-3.0 GPUs is near, but what about now you say?
Z68 is a great cost effective platform, upgradeable to Ivy Bridge in the future.
Are you doing Eyefinity? multi GPU rig now? If so great!, use this board now and just wait for the dual GPU 7990 PCI-e 3.0 board...
3 ASUS EAH6970 in Tri-Fire and Battlefield 3 using 3 Dell U2412M LCD panels in Eyefinity configuration. i7-2600K, 16gb Mushkin redline, ASRock Z68 Extreme7 Gen3.
I went weeks hoping to get smooth graphics, driver updates, game updates, and I used MSCONFIG to remove all non-essential programs...
The Antec 900 (and 902) are very nice cases, It was annoying when I figured out I needed a new case for my build. I agree, 2 HD6970 plus 4 3.5" disks (and perhaps even a couple of 2.5" SSD) would fit, but it's a tight mid-tower if you want to try to use all it's internal bays and squeeze in a...
I had an ANTEC 900 (similar to 902), while you can fit the card, you will need to have one internal drive bay empty per video card. Perhaps you could fit some disk types, I'm not sure, but this is true for 3.5" sata disks.
I have a 6 drive raid 10 array, and in the Antec 900 I had just enough...