I am trying to figure out why my two Graphics Cards are not both running in PCIe 2.0 x16 speed. I have one that seems to be running in at x16 speed, but the other is only at x8 speed. One card is in the first slot and the second card is in the 3rd slot. I realized that due to the fact that I have a Sandy Bridge Processor, it appears I can't get the 3.0 bandwidth, but I would assume I should still be able to get both to run at 2.0 x16. I have checked the bios and all slots are set for Gen 2. I am checking this with GPU-Z and even under stress the card will not kick up to x16.

ASRock X79 Extreme 11
Intel i7 3930
32GB Corsair DDR3 Ram
2 EVGA GTX 780 in SLI mode
850 W Power Supply

Current Bios is: 3.20 version

Any help would be appreciated.