I don't think there's a problem with any of the risers or cards. when I plug in cards 1,2,3, and 4 into the first four slots on the motherboard, they work fine. If I plug in cards 1,2,5, and 6 into the first four slots, they also work fine. I have also tried cards 1, 2, 5, and 6 in slots 1, 2, 5, and 6 with success.
I have tried both Gen1 and Gen2. I also tried turning off the PEGPORT Config PCIEX6_1 Link Speed.
Right now, I have six cards hooked up and it won't go back to the bios when it reboots. It just goes to Hive.
It's the motherboard, I have a AMD motherboard that's this bad too, it has more than 4 slots and when I insert up to 6 GPUs no matter what I try it won't work, I end up getting a new gigabyte motherboard, more stable and all cards are recognized instantly, have you try updating bios like some recommend already?