GPU on Tertiary Riser shows Unknown Device, other GPUs working: DL380 Gen10

[Backroads4me]

I have 4 identical GPUs I'm attempting to use on a DL380 Gen10 (868703-B21).   3 work perfectly with one on the primary riser x16 slot, two on the secondary x16 slots using riser 826704-B21.   I also have 826700-B21 as the tertiary riser.  The deivce is recognized in slot 7, but the GPU shows as "Unknown Device".  
- I've updated the system rom (Feb 2024), iLO5 (Jun 2024)and using the most recent SPP (Apr 2024).
- Switching the "working" GPUs from the other slots to the tertiary riser has the same result.
- The lights on the tertiary GPU are on and the fan spins initially on power up, so it appears to be getting power correctly.

Any other suggestions of what I should check or change?

Thanks 

[Suman_1978]

Hi,

What is the GPU model number and Firmware on it?
This "unknown device" you see this in Windows Server Device Manager?
Is there a second processor installed on this server?
How many power supplies does this server has?

There are some limitations or configuration changes depending on the GPU installed, please check the QuickSpecs.

Thank You!
I work with HPE but opinions expressed here are mine.

[Backroads4me · Accepted solution]

After taking everything out and cleaning all of the PCI connections on both the card, the server and the tertiarry riser, I was able to get it to work.  Somewhere along the path I wasn't getting a good connection.

Thank you

[Sunitha_Mod]

Hello @Backroads4me,

Great! 

We are glad to know you were able to find the solution and we appreciate you for keeping us updated.