[1 LTC BOUNTY] Getting mobo to detect 5th GPU

[miztaziggy]

I have a Gigabyte 990XA-UD3 board.

It has in this order:
PCI x1
PCI x16
PCI x1
PCI x16
PCI x16

Now with 3 cards plugged directly into board in the 3 x 16 slots all 3 are detected and work fine.

With cards in 1x risers, the card in the second (middle) x16 slot isn't detected. I have 5 cards plugged in but Win 8 only sees 4.

I have tried to short out pins A1 and B17 on the x16 slot, but with them shorted the mobo won't turn on. I have tried this on 1_x16 and 2_x16 slots and it won't boot with either of them shorted.

I saw someone post about changing PCI latency to 32 which apparently might help, but there is no such setting in the BIOS.

What's the trick to getting the BIOS to detect this card?

[Boxman90]

Is that shorted the 16x slot with the card in directly or with all cards in via a 1x riser?

[miztaziggy]

Is that shorted the 16x slot with the card in directly or with all cards in via a 1x riser?

No that's the 16 slot shorted exactly the same way as I would with the 1x slots. Short the socket and then plug in the riser.

Do I need to short pin A1 and pin B81 instead on a 16 times slot?

[Boxman90]

Is that shorted the 16x slot with the card in directly or with all cards in via a 1x riser?

No that's the 16 slot shorted exactly the same way as I would with the 1x slots. Short the socket and then plug in the riser.

Do I need to short pin A1 and pin B81 instead on a 16 times slot?

No, it should be shorted exactly as the 1x bridge. PCI-e is a bus, so the slots are actually interconnected on the same lane. I got mine working with 4GPU's that way, never tried 5.

[dual6990s]

Powered risers?