I was testing this myself earlier in the day while setting up a 3-way SLI GeForce GTX 680 setup, but the cards refuse to run in PCIe Gen 3 mode. There seems to be a little issue with the driver.I was testing this myself earlier in the day while setting up a 3-way SLI GeForce GTX 680 setup, but the cards refuse to run in PCIe Gen 3 mode. There seems to be a little issue with the driver.
Basically, the video adapter does not support PCI Express Gen 3.0 on motherboards powered by the X79 chipset.