Having an issue with the Asrock BTC Pro board recognizing all 3 of my Sapphire Tri-x 290's. Windows 7 64-bit - It sees 2 of the cards (all 3 on risers in 1x PCIE slots) but can't get it to see the third for the life of me. Confirmed the 3rd card works as I swapped it with the 2nd card to ensure it CAN be seen, which it can, just not 3 all at once. I am running two 850w corsair PSUs together for the board (with the an adapter to combine them)

Any ideas? Does the presence pin on the 3rd PCI 1x slot need to be shorted?

You'd think that the board DESIGNED for running risers as a rig for mining would support all cards out of the box.