H12SSL-NT: Intel X710-DA4 card works in X16 slots but not X8 slots

lunadesign

Active Member
Aug 7, 2013
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I have a known good Intel X710-DA4 10G ethernet card. This is a PCIe 3.0 X8 card. I plugged this card into the H12SSL-NT motherboard and it works on all 3 X16 slots I tried but not in either of the X8 slots.

In slots 1, 3 and 5 (all X16), the BIOS will fully make it through POST and the card shows up in the BIOS menu.

In slot 2 (X8), the BIOS will fully make it through POST but the card does *not* show up in the BIOS menu.

In slot 4 (X8), the BIOS will *not* make it through POST. Instead it gets stuck at DXE--BIOS PCI Bus Enumeration 94.

Since this is an X8 card, I'd really like to to use it in one of the two X8 slots on this motherboard. I don't want to waste an X16 slot.

Any ideas?
 

lunadesign

Active Member
Aug 7, 2013
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first force the PCIe mode of these slots to 3.0
Oddly enough, I haven't been able to find a BIOS setting that allows me to specify GEN 3 vs GEN 4. The only per-slot PCIe options I see are:
  • OPROM (choices are Disabled and EFI, currently set to EFI)
  • Bifurcation (choices for the x8 slots are Auto and x4x4, currently set to Auto)
what CPU are you using ? properly seated ?
I'm using an Epyc 7262. It's my first Epyc CPU build but I've installed quite a few CPUs before. I'm 99% sure it's seated correctly as it's been working normally in various tests for several months.
 

lunadesign

Active Member
Aug 7, 2013
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i would open a case at supermicro, needs the serial-number of the board.
Yep - already did. Still working through the initial stuff with them (trying out the latest BIOS and IPMI). No resolution yet. I'll report back with any interesting developments.
 

RolloZ170

Active Member
Apr 24, 2016
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if there are bifurcation settings auto and 4+4, maybe the boards sets 4+4 by mistake. makes sense but it is an explanation but not a solution.
 

jpmomo

Active Member
Aug 12, 2018
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i have an h12ssl-i and had to have it rma'd 1 time due to strange behavior of pci slot 2. Not sure what was wrong, but when I tried to put an x8 nvme pci card in it, the bmc got corrupted and the board wouldn't post. there was never any explanation as to why it happened.