I wont debate the Win 8 vs Win 7, I have used both 8 and 7 before for mining rigs, I have seen no problems nor heard of any legit information saying theres a problem with 8. From what I have read in other tech site not forums, is there is no difference in the kernels as far as GPUs are concerned besides a few small additions hence why most drivers didnt not change from 7 to 8

I have tested all the cards in the primary pcie 16x slot, and ran them on another computer of mine, all cards show up in both systems Device Manager and in CGminer they all mine

The PCIe slots are Gen 2 and function as 2x16x, 1x8x, and 1x4x

In other posts these motherboards have been said to have 6 cards running on them.