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December 13th, 2024 00:37
Dell 5820T Workstation PCIe Bifurcation problem - I’ve tried everything!
I’m trying to use a 4x M.2 NVMe to PCIe add-in card, and I can’t get the dang thing to work! At least not in this computer. It shows 1 of 4 drives only.
I can't find any BIOS setting to set bifurcation to x4x4x4x4. Is there such a setting? My understanding is turn off VROC, turn off VMD, and it just... works? That surprises me, but after spending way too many hours searching forums, that's how it seems?
I’ve tried all the standard things ;_;
- From googling, the 5820 should support PCIe bifurcation- many people have said they use it.
- BIOS version 2.36.0 from May 10, 2024
- I am using a PCIe x16 slot that is wired x16. This tower has two electrical x16 slots, and I have tried both, including the one nearest the CPU
- This is a Xeon W-2125 processor. It supports bifurcation as far as I can tell, and I have plenty of PCIe lanes
- I have VROC turned off, and I have no VROC key installed
- VMD is off
- There is no specific setting in my BIOS that I can find to specifically turn a PCIe slot into x4x4x4x4 or other configs, but as far as I can tell, I don’t need to for it to work
- I have tested the card on another system with an ASUS TUF GAMING B650-PLUS WIFI motherboard, where after manually configuring the mobo in the BIOS to RAID mode (clearly it’s not literally RAID right?), I could see all 4 drives and use them individually in Windows. I could also do x8x8 and see two of the drives. So the card works, at least in that context
- This is the card in question. It’s JEYI but people in the comments say it works. Also, previous bullet point ^
- In the BIOS, under system info, under PCI information, it says the slot is populated by “Mass Storage,” which seems expected
I am stumped. I can boot into TrueNAS Scale (on a different drive), and it can see the first drive just like the BIOS. But the BIOS just cannot see the other drives.
Does anyone have an idea? I’m down to do any testing and settings changing suggested! There’s gotta be some random thing I’m missing.