New Asus X870E Strix board - M.2 drive disappearing

[Cheairnyndahl]

Hello, just installed my new Asus X870E-E Strix motherboard, loving it so far. When I initially got in to Windows, all of my drives were present (even the new one that wasn't formatted yet was showing in Disk Management) - I updated everything in terms of latest drivers for the motherboard etc, rebooted and enabled EXPO on my RAM, set to 6000MHz with voltages set, didn't touch any other settings...

And now one of my M.2 drives is not showing up in BIOS or in Windows?  I've tried changing the BIOS setting for Bifurcation to GPU+M.2 mode, that doesn't help.  Any suggestions as to what else I can try?  I have a feeling it's related to the whole thing of the GPU slot & the M.2-2 & M.2-3 sharing bandwidth, but the drive that's in one of them is showing up while the other is not now.
I'm going to try disabling EXPO & see if that helps for some reason... wouldn't make any sense if that was it, but perhaps the BIOS version I'm on is messing something up.

[voltronad]

I can live with that lol - I have a 4090 and everything looks great so I won't fret about 1-5%.  I have 3 M_2 drives and need them all so I can deal with it.  Thanks for the info!

[Cheairnyndahl]

If you only have 3 you could always run 1 in m.2-1 and the other 2 on the chipset slots.

There's also the option I went with on my old system, got a Sabrent PCIe x4 slot m.2 card, I'm using it in the slot that's physically wired for x4 4.0 according to the manual and it basically runs at full speed. I have a Samsung 4TB 990 Pro in that that has most of my games on it, and the card's heatsink does a good job keeping the drive cool too.

Link if you're interested: https://www.amazon.com/Sabrent-NVMe-PCIe-Aluminum-EC-PCIE/dp/B084GDY2PW/ 

[voltronad]

I'm actually so dumb - I moved my 2 extra M_2's over to slots 4 & 5 and now PCI is running at x16.  My samsung ssds are PCIe 4.0 only anyway so slots 4 and 5 are perfect.

[Cheairnyndahl]

The heatsink on the 4th/5th slot is pretty basic & doesn't do a great job, to the point where I'm replacing it with some cheap aftermarket heatsinks just to see what the temperature differences are. 

But yeah the bottom two are chipset m.2 slots share their x4 so I think if you use both at the same time speed might be effected, but it's still plenty fast. 

[Cheairnyndahl]

Figured I'd tag you in with the post I just made, showing some real-game results (albeit at 5120 x 1440 resolution) with an RTX 4090 on x8 vs x16 bandwidth.

[Cheairnyndahl]

You have to keep in mind that the reason it does that with 4 drives is because 2 of the 4 have to be in the cpu-linked m.2 slots. It's more of because of the way they made the traces on the motherboard. 

It sucks, but it's the same way with the new Intel boards, if there's more than 1 drive connected to the cpu directly it slows down the top x16 slot to x8.

I still have yet to have the issue again, right now I'm running where I have to have EXPO enabled because an EXPO profile is required to run asynchronous clocks for the ECLK OC I'm running. I'm honestly not sure if it's a fluke, if reseating the CPU & drives helped, or what. 

[Inugami0909]

Mainboard defect. It is defective. I first contacted Asus on October 31, 2024, but they said they did not know and told me to ask the distributor. The distributor also said they did not know and that it was the first time they heard of it. I exchanged it at the place I bought it from and it is now working properly.

Please exchange it. It's defective.

[hydrus]

Do you mean you had the same stuttering issue and after replacement it went away? Or do you mean the NVME drives appeared after replacement?

[Inugami0909]

It's a motherboard defect.
After installing an SSD in the M.2 3rd slot
When EXPO is activated, slots 2 and 3 are deactivated.
Only slot 1 is alive.
When EXPO is activated, slots 2 and 3 are dead.
It's a motherboard defect.
Please replace the motherboard
The symptom will disappear.
I discovered it on October 30, 2024 and told ASUS about the motherboard defect on October 31, 2024, but they ignored it and said that it was a SSD and CPU defect. However, it was a motherboard defect.

Symptoms:

After purchasing on October 29, 2024, M.2 SSD was installed in PCIE5.0 slot 3 and OS was installed.
When EXPO is activated, booting is not possible, no bootable OS.
When checked, M.2 slot 3 was dead.
After entering BIOS and rebooting, M.2 slot 3 was activated again.
Boot was successful, but memory and SSD malfunctions occurred.
The malfunction was confirmed to be caused by M.2 disconnection from the motherboard.
When EXPO was deactivated, M.2 slot 3 was continuously activated.

Summary: When memory overclocking such as EXPO was performed after installing SSD in M.2 slot 3, M.2 slot 3 died (deactivated).
When rebooting, activation and deactivation were repeated.

ASUS and AS distributors responded that it was a defective CPU, SSD, and RAM.
But when the motherboard was actually replaced, the symptom disappeared.
The symptom disappeared, but I am afraid that the symptom will occur again. The rest
I am using it by installing it in the M.2 1st slot.

I confirmed that the M.2 1st slot never dies.

It's a motherboard defect.
After installing an SSD in the M.2 3rd slot
When EXPO is activated, slots 2 and 3 are deactivated.
Only slot 1 is alive.
When EXPO is activated, slots 2 and 3 are dead.
It's a motherboard defect.
Please replace the motherboard
The symptom will disappear.
I discovered it on October 30, 2024 and told ASUS about the motherboard defect on October 31, 2024, but they ignored it and said that it was a SSD and CPU defect. However, it was a motherboard defect.

[hydrus]

I see. So when you placed your M.2 drive in M.2_1 the symptoms went away. You also replaced the board. Yes I believe it is a BIOS problem and hopefully updates can fix it in the future. Seems now with EXPO on it affects some sort of PCI express lanes bandwidth. It causes M.2 drives to disappear from M.2_2 and M.2_3 slots and also in my case GPU PCI express speeds to be stuck upon some reboots.