GPU not showing using lspci in a UEFI Mint

Intel(R) Xeon(R) Gold 6126 CPU @ 2.60GHz

Your system should be well supported by the 4.15 kernel. Are you installing on bare metal or in a VM?

No its not a VM, i have the machine

It’s a mystery why even the PLX bridges don’t show up, any errors in dmesg about them?
dmesg |grep 10b5
Otherwise I can only suspect the sxm2 add-on module or power connectors not properly seated so it only sometimes works. Has the server been moved/opened between OS installations?

The Devices are properly set.
And the server has not been moved and i am not able to understand the same os once shown devices and then it fails to do.

Is there something in bios or efi settings

I can’t think of any bios setting that would have this kind of effect. Maybe check ‘above 4G decoding’ but this would only have influence on function, not visibility. I think you should rather revert to Supermicro support, or did the dmesg output show anything about the bridges?

Any updates on this thread ? I am having the same issue with Supermicro.