GPUs on USB risers not being recognised

[htzeng84]

Hi,

I have an A88X-PRO AMD MB, running Win 10 and trying to install 4 RX580 4GB GBPs.

Installing 2 GPUs onto the MB directly work fine (PCIE_16_1, PCIE16_3), however any that are connected by to the board via 16-1 PCIE USB risers do not work.  I've tried sourcing risers from 2 suppliers (12 risers in total), as I had heard that some risers are defective, but the GPUs are still not recognised by the MB.  They light up, but the fans don't spin and nothing appears in Device Manager.  Also tried the trick of shorting one of the PCIE1 connectors on the MB, but still no luck.

Any help / suggestions would be most welcome!

Thanks.

[hagbase]

Set PCIe Gen to 1 in bios for your slots if auto doesn't work.

[stoniestfool]

ager.  Also tried the trick of shorting one of the PCIE1 connectors on the MB, but still no luck.

Any help / suggestions would be most welcome!

Thanks.

Well that was dumb. You damaged the motherboard. I have never had a faulty extender yet.

[igotfits]

Also tried the trick of shorting one of the PCIE1

umm what? shorting out electronics as sensitive as the MB is a trick?

update your bios to the latest,  remove all GPUs, connect one gpu to the first pci with the riser only. connect the screen directly to that GPU an not the internal graphics. let us know what happens?

[htzeng84]

Thanks for the suggestions. BIOS is updated to the latest.  I've already tried looking for the GEN settings in the BIOS but found nothing relevant.

By shorting, I mean this:

http://en.community.dell.com/support-forums/servers/f/956/t/19373337

No issues with the MB afterwards, except still no detection.

Will try running DDU again, and then installing the GPUs one by one via the risers.

[Undefined31415]

ager.  Also tried the trick of shorting one of the PCIE1 connectors on the MB, but still no luck.

Any help / suggestions would be most welcome!

Thanks.

Well that was dumb. You damaged the motherboard. I have never had a faulty extender yet.

Also tried the trick of shorting one of the PCIE1

umm what? shorting out electronics as sensitive as the MB is a trick?

update your bios to the latest,  remove all GPUs, connect one gpu to the first pci with the riser only. connect the screen directly to that GPU an not the internal graphics. let us know what happens?

You guys haven't been around long enough to remember this. https://bitcointalk.org/index.php?topic=36061.0

I have only ever needed to use this trick when I first started mining and used old motherboards, such as an Asrock n68s-UCC. It's definitely less common for more recent motherboards to require this, but it's still sometimes needed.

@OP: To test your risers, have you tried using only one GPU with a riser into the x16 slot?