Asus Z170-A additional pci-e slots not detecting devices

[DrNicT500]

I'm trying to crossfire my gpus on this build.

Specs:
Asus Z170-A motherboard
Intel core i5-6600
m.2 ssd

When I have my gpu in the first pci-e slot, it detects it fine and boots all happy.

When I have the single gpu in the second slot or third slot, the bios does not detect a device nor does windows see it (verified using the integrated gpu)

When I have a gpu in the first, and second or third slot, only the first gpu functions and is detected.

With the integrated graphics disabled (to my knowledge) the above tests have the same results.

I have tried many different gpus, so I see specifying which one(s) irrelevant.

Am I missing some setting? This board kinda blows...

 

[bjornl]

Not helping you, just commiserating. (sorry). I've had bad luck with several recent ASUS boards as their QA seems to have dropped off. But if you don't mind trying one thing.... perhaps a BIOS flash to the most recent might help.

 

[Paul NZ]

This may or may not have anything to do with it. This is from the ASUS site

1: The PCIe x16_3 slot shares bandwidth with SATA6G_56. The PCIe x16_3 is default set at x2 mode. Supports Intel® RST for PCIE RAID storage.
*2: Supports PCIE RAID configurations via onboard M.2 and PCIex16_3.
*3: M.2 shares SATA mode with SATA Express. Change this item before installing M.2 SATA devices.

 

[DrNicT500]

Not helping you, just commiserating. (sorry). I've had bad luck with several recent ASUS boards as their QA seems to have dropped off. But if you don't mind trying one thing.... perhaps a BIOS flash to the most recent might help.

Thanks! I have already tried re-flashing the bios with no effect. I've also pulled the bios battery and cleared the cmos a few times

 

[DrNicT500]

This may or may not have anything to do with it. This is from the ASUS site

1: The PCIe x16_3 slot shares bandwidth with SATA6G_56. The PCIe x16_3 is default set at x2 mode. Supports Intel® RST for PCIE RAID storage.
*2: Supports PCIE RAID configurations via onboard M.2 and PCIex16_3.
*3: M.2 shares SATA mode with SATA Express. Change this item before installing M.2 SATA devices.

This was one of my first suspicions, but what I tried was removing my ssd, changing the setting back along with resetting the bios, and I still have the same issues.