Question WD SN850 M.2 NVMe SSD is not recognised in BIOS ?

Jul 10, 2022
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Looking for a sanity check. I've been building my own PCs for 20 years and working in IT the past 10 years. I've specced and built 100s of desktops for clients, so I'm not new to building PCs, ensuring compatibility and such, but I'm running into a problem that has me gaslighting myself while trying to troubleshoot it.

Key Components:
Motherboard - ASUS X99-A/USB3.1
M.2 NVMe SSD - WD SN850 2TB

For context, my entire rig was modeled after PCs specced for an engineering firm client. Originally, they were not built with NVMe drives, only SATA SSD, but the motherboard was chosen to allow the upgrade in the future. After their first batch of PCs were built with SATA SSDs, we decided to upgrade to Samsung NVMe drives for the next batch (Can't remember the model off the top of my head) and I setup at least a dozen PCs with those NVMe drives without issue. The only difference between my build and those builds are a few more HDD and SSD drives, an RTX GPU rather than a Quadro GPU, and a much beefier PSU.

Now for the nitty gritty. No matter what I do, I cannot get the BIOS to recognize the SN850 as a storage device. The previous Samsung drives needed no BIOS update or config changes to be recognized when I set them up for the client, default settings worked without issue. Here are the steps I've taken so far:
  • Reset CMOS
  • Updated BIOS firmware to newest version (Interestingly - the M.2 slot setting had NVMe in the name of the setting prior to the update. It now only references M.2 and not NVMe)
  • Reset CMOS again
  • Removed all other storage devices
  • Quadruple-checked all BIOS settings concerning M.2
    • Disabled ASUS Hyper Kit, allowing M.2
    • The M.2 slot can be disabled if the PCI x16_4 slot is set to be used instead, I am not using that slot and the PCI setting is set to Auto to enable M.2
    • Disabled Fast Boot
    • Disabled Secure Boot and reset Secure Boot Keys
    • Tried every possible different configuration of the various CSM settings for UEFI and Legacy
  • Re-seated SN850 into the M.2 slot
  • Double checked compatibility settings for SN850
    • SN850 is M.2 M-key 2280 PCIe Gen4 x4
    • Data sheet shows backward compatibility with PCIe Gen3 x2
    • Motherboard has an M.2(Socket 3) M-key PCIe Gen3 x4 slot and is compatible with various size strorage devices including 2280
      • Gen3 x2 is not Gen3 x4 obviously, but we all know PCIe lane compatibilty, I'd just lose some speed due to only having 2 lanes
  • Re-seated SN850 into the M.2 slot again - still no recognition
  • Re-attached OS drive and booted into Windows after nearly giving up
  • Checked that Windows Disk Management wasn't miraculously recognizing the drive without the BIOS recognizing it - it wasn't. (Believe it or not, I've seen this happen multiple times with other builds)
  • Checked that Western Digital Dashboard wasn't miraculously recognizing the drive as well, no dice.
I'm at my wit's end trying to get this to work and I haven't found anything that says it isn't compatible. Ultimately, I don't have to get it working in the M.2 slot yet as I have plenty of other drives and I've ordered a PCIe slot adapter in order to hopefully use the drive for now. Eventually I'll be upgrading my motherboard - at which point I'll be sure to purchase one I can confirm works with the SN850 whether by QVL list or multiple online confirmations. Adapter should be here tomorrow and hopefully that will allow me to ensure the drive isn't just DOA. Starting to feel like that's the only possible option.

Any thoughts? Am I crazy?
 
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Jul 10, 2022
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Tried the WD SN850 2TB in another PC ? Could be DOA
Sadly, I don't have another motherboard with an M.2 slot to test it on at the moment. As stated near the end of the post though, I have a PCIe adapter card coming, so I can at least test it in that on the same motherboard to ensure it's not a DOA issue. Should have that by tomorrow to test.
 
Jul 10, 2022
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Update: PCIe Card Adapter showed up this afternoon, still no BIOS recognition of the SN850 from either of the two available PCIe x16 slots available (No onboard graphics, so I couldn't test the GPU slot).

Also showing up this afternoon, was my brother with his old Z730 AORUS rig. The drive is recognized in his BIOS, so I can confirm that the drive is not DOA.

What this also confirms is that there is some type of compatibility issue with the BIOS on my ASUS motherboard. All compatibility within documentation has been met, so it seems to me that some of the industry standards for documenting compatibility around M.2 are sorely lacking, or maybe it just was at the time of my motherboard's manufacturing. It was the very early days of NVMe becoming a consumer product after all. The manual still references NGFF for M.2.

My question at this point is, WHAT is the compatibility issue?
 
Jul 10, 2022
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Don't know.

But I can tell you that this forum is knee deep in non-recognition in BIOS issues for the last few months. I have not followed it closely....there may be some clues among the various threads.
I've noticed that, been trying to sift through them since before I posted and continuing even after. About 95% of the ones I've read through so far are people not understanding the differences in SATA and NVMe for M.2 slots or not updating their BIOS to the latest version/settings BIOS config properly. The other 5% seem to be something similar to my issue.

Gonna contact ASUS and see if I can possibly get any information from them.
 
Jul 10, 2022
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The newest Bios is a beta version

Did you try with version 3902 ?
There is an old discussion with a guy using 3801 with success on a smilar mobo
I saw that discussion while troubleshooting yesterday and got a little bit of info from it, but didn't think it was the same model as USB3.1 was never specified.

I did initially think maybe the Beta version could be part of the problem once I realized that 4101 was marked as Beta. I pscyhed myself out to troubleshoot more BIOS versions, was thinking there was no way they would remove compatibility in a later version, but I suppose it wouldn't hurt to try to backtrack the BIOS firmware to 3801 (latest stable) just to be sure they haven't screwed up the NVMe with the Beta versions. I'll give that a shot tomorrow. Thanks for reminding me to revisit that!
 

KyaraM

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Mar 11, 2022
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Does it have to be the SN850? You could simply use an older drive, considering you won't ever get the actual speed out of it anyways; that system cannot run PCIE 4.0 M.2 SSDs at full speed, ever. It will be limited to PCIE 1.0 or 2.0 speed, I'm not sure which. Most likely no difference to a SATA-SSD. Would also save some money if you can return it. Or the money can be invested into a bigger drive...
 
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I saw that discussion while troubleshooting yesterday and got a little bit of info from it, but didn't think it was the same model as USB3.1 was never specified.

I did initially think maybe the Beta version could be part of the problem once I realized that 4101 was marked as Beta. I pscyhed myself out to troubleshoot more BIOS versions, was thinking there was no way they would remove compatibility in a later version, but I suppose it wouldn't hurt to try to backtrack the BIOS firmware to 3801 (latest stable) just to be sure they haven't screwed up the NVMe with the Beta versions. I'll give that a shot tomorrow. Thanks for reminding me to revisit that!
If you ever get this to work you might be disappointed to find that perf wise there is very little if any diff from a quality sata ssd.
 
Jul 10, 2022
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The newest Bios is a beta version
Did you try with version 3902 ?
There is an old discussion with a guy using 3801 with success on a smilar mobo
So I finally got back to this. Reverted BIOS to version 3801 (latest non-beta version). No dice... :(

No word back from ASUS yet either.

Does it have to be the SN850? You could simply use an older drive, considering you won't ever get the actual speed out of it anyways; that system cannot run PCIE 4.0 M.2 SSDs at full speed, ever. It will be limited to PCIE 1.0 or 2.0 speed, I'm not sure which. Most likely no difference to a SATA-SSD. Would also save some money if you can return it. Or the money can be invested into a bigger drive...
It doesn't have to be, no - but I purchased it as one of the fastest drives on the market currently for a near future upgrade of my motherboard, just wanted to utilize the drive in this setup until then. I knew going into the purchase I wasn't going to get anywhere near the full performance the drive is capable of, it would have been limited to PCIE 3.0 (not 1.0 or 2.0), and I was fine with that. As for space, I've got plenty of other SATA SSDs and HDDs. I specifically chose the SN850 for the high performance benchmarks compatible with my planned upgrade around the corner.

Just not so happy with my current motherboard not even recognizing it when everything says it should be compatible, other than it not appearing on the QVL List, but there isn't a single M.2 drive on that tiny list and there's no other storage drive QVLs listed for that motherboard.

If you ever get this to work you might be disappointed to find that perf wise there is very little if any diff from a quality sata ssd.
I'm disappointed that it's not recognized is all, I knew the performance would be bottlenecked by PCIE 3.0 before purchasing the drive and checking for compatibility. ASUS QVL doesn't list any M.2 drives for this motherboard, but I knew it had an M.2 slot that could be utilized due to having built at least a dozen of this same PC setup for clients using a Samsung M.2 drive years ago.

Oh well, it'll be a brand new, fresh drive for the future motherboard and CPU upgrade.
 

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