PCIe nvme card in PCI x4 slot prevents booting even from USB. Why? HP EliteDesk 800 G4 Win11

[wwcanoer]

I was hoping to add two PCIe x4 nvme cards but when I add a card in only the white x4 slot, it prevents booting from both my normal Win11 nvme boot drive  and a USB.  When installed in the x16 slot everything is fine but (1) I want two cards and (2) x16 is for a graphics card, right? so I would lose that expansion option.

HP EliteDesk 800 G4 slots:

Motherboard viewer shows:

8. PCI Express x4 (white) 
9. PCI Express x1
10. PCI Express x16 (black)

https://h10032.www1.hp.com/ctg/Manual/c06524328.pdf

Specifications page says

1 M.2 2230; 1 PCIe 3 x16; 2 PCIe 3 x1; 1 PCIe 3 x16 (wired as x4); 2 M.2 2230/2280

The PCI card is Ugreen PCie 4.0 to M2 NVME Expansion Card 30715

UGREEN M.2 NVMe to PCI-E Gen4 / Gen3 with Heatsink
Connector: M2 M key
Compatible PCIE slots: X4 / X8 /X16
Theoretical transfer rate: 64Gbps ( pcie gen4 ), 32GBps ( pcie gen3)
Compatible system: Windows, mac, linux

https://www.tokopedia.com/ugreenofficial/ugreen-pcie-4-0-to-m2-nvme-expansion-card-30715 

The card is x16 long but only has wires connecting to the first x4 pins.  So, I expected it to work in the white slot.

In the x4 slot, the bios correctly recognizes the nvme drive (ADATA SX8600 Pro  Gen 3 x4 2TB) in the card and the bios hardware tests pass but something is interfering with recognizing a boot drive.  Windows drive is the first boot option and USB the second. 

Any ideas?? Or just the way it is. 

[erico]

How about rephrasing this statement. "The card is x16 long but only has wires connecting to the first x4 pins."

I do not understand that, considering that there are no wires on the adapter, only traces.

This statement is also not cleat. Kindly rephrase it. " I want two cards"

This is the reason I tend to stick with mainstream products. I have an ASUS adapter that I have used for years without issue.

USB should be the first boot option.

What type of drive is your Windows boot drive? With the information you have provided, it is not clear at all.

[wwcanoer]

wire = trace = connections = electrical paths = pins

The card is x16 long but only has x4 traces because that's all you need for one nvme connector/disk.

"I was hoping to add two PCIe x4 nvme cards."  I don't know what's unclear about that. 

There's limited selection here in Indonesia.  A 4-disk nvme pcie card is $85 and a 1-disk card is $10.  None will be big-name brands but Ugreen does sell in Europe and the US too.  However, the card appears to have almost no electronics (perhaps only the activity sensor and LED), it's primarily just traces adapting from a motherboard PCIe connector to an nvme connector.

(I'm guessing that there's some shared resource between the built-in nvme slots and the x4 slot that means that an nvme can't go in the x4 slot even though  the BIOS shows the two different drives, but can't tell that one contains the operating system..

Right now, I've deleted all partitions on my boot drive and reinstalling win 11 because previously when installed Win11 it said that the partitions where in a non-standard order (I moved it from another computer that dual booted win10/11).  Maybe I will get lucky and that will solve it.

[erico]

"(I moved it from another computer that dual booted win10/11)"

I can see how that would mess things up. 

Reinstalling Windows 11 should help.

You still have not answered my question about your boot drive.

""I was hoping to add two PCIe x4 nvme cards."  I don't know what's unclear about that."

Use a 2 card PCIe adapter. That was my solution.

"wire = trace = connections = electrical paths = pins" It is just semantics, but it is helpful  to be specific when discussing PC hardware.

"The card is x16 long "  The card is x16 format but wired as x4.

[wwcanoer]

Reinstalling Windows didn't help. (removed all sata drives. No change. 

Works: Moved the fresh Win 11 install to the White PCIe x4 slot with nothing in the motherboars nvme slots and it booted normally! (Also all sata drives disconnected).  So, nothing wrong with using a PCIe nvme adapter in that slot.   Now to see what happens when I populate the motherboard slots.

Perhaps because I had my boot drive in motherboard nvme slot 2 instead of slot 1?  (I hadn't intended that. Once they had the same heatsink, I forgot which was which. It worked fine so I didn't change it.)

Works: Boot drive on white x4 PCIe + drive in motherboard NVMe slot 1

Works: Boot drive on white x4 PCIe + drive in motherboard NVMe slot 1 + drive in NMVe slot 2

(however, initially had a BSOD but auto-restart booted fine.

So, Can I move my boot drive to motherboard NVMe slot 1?  (The PCIe card has a long heat sink, so better if I can move the bare nvme card there.)

Note: This user did use the white x4 PCIe slot for a third NVMe drive, on an 800 G4 SFF (mine's the WKS tower).  Perhaps I should be updating the BIOS but will first continue without doing that.

https://h30434.www3.hp.com/t5/Desktop-Hardware-and-Upgrade-Questions/upgrading-drives-on-elitedesk-8...

https://h30434.www3.hp.com/t5/Desktop-Hardware-and-Upgrade-Questions/Upgrading-HP-EliteDesk-800-G4-S... 

[wwcanoer · Accepted solution]

Solution? : When the white x4 PCIe slot is used for NVMe, then the boot drive must be in this slot. 

Why: Moving the boot drive to motherboard NVMe slot 1 failed to detect an operating system.  I started with boot drive on motherboard NVMe slot 2. 

Note: When both motherboard NVMe slots and the black x16 PCIe slot are used, then the boot drive was fine on motherboard slot 2.

I wonder if a BIOS update would change this....

[wwcanoer]

Successfully installed four nvme drives, booting off the one in the white PCIe x4 slot.  Ugreen adapters in the x4 and x16 slots plus the two onboard nvme slots.

Here's the results: