Question Samsung 990 Pro is stuck at PCIe Gen4 x2 Instead of x4, but this same setup worked fine with previous SSD ?

[Akrad]

Hi everyone,

I recently noticed that my Samsung 990 Pro 2TB SSD is only running at PCIe Gen4 x2 instead of the expected x4, even though it’s installed in the correct M.2 slot on my motherboard.

I’m running a Ryzen 7 7800X3D on an MSI B650 Gaming Plus WiFi motherboard, with an RX 7900 XTX and 32GB of DDR5 6000MHz RAM. The SSD is installed in the M.2_1 slot — the one closest to the CPU — which should support Gen4 x4. No other SATA or PCIe devices are connected besides the GPU and the onboard WiFi. The BIOS is fully updated, and the slot is set to Gen4 manually (I’ve also tested it on Auto). I’ve double-checked every PCIe and lane-related setting I could find in the BIOS.

Samsung Magician reports the interface as PCIe Gen4 x2, using the Microsoft NVMe driver and firmware version 4B2QJXD7.

Here are the benchmark results from Samsung Magician:

Sequential Read: 3637 MB/s

Sequential Write: 3459 MB/s

Random Read: 887,207 IOPS

Random Write: 820,312 IOPS

These numbers clearly reflect a Gen4 x2 connection.

What’s strange is that my previous SSD worked perfectly fine at Gen4 x4 in the exact same configuration, without any BIOS or hardware changes. This issue seems specific to the 990 Pro, and I suspect it’s been like this since I installed the drive — I just didn’t notice it until now.

Has anyone experienced something similar with this drive, or could this indicate a hardware or firmware issue with the SSD itself?

Thanks in advance for any help or insights.

 

[helpstar]

reset the BIOS then try magician again

check the correct seating of the SSD in the slot, unplug it and replug again
did you tighten the M.2 screw ?

7E26v1K4(Beta version) is installed on the motherboard?

update the SSD if a firmware is available
update nvme driver/AMD

 

[Akrad]

reset the BIOS then try magician again

check the correct seating of the SSD in the slot, unplug it and replug again
did you tighten the M.2 screw ?

7E26v1K4(Beta version) is installed on the motherboard?

update the SSD if a firmware is available
update nvme driver/AMD

Thanks! Yeah I already tried reseating the SSD a few times, it’s properly screwed in and detected. I’m on the latest BIOS (7E26v1K4 beta), the SSD firmware is updated (4B2QJXD7), and I’m using the default Microsoft NVMe driver since Samsung doesn’t offer one for the 990 Pro.

I also did a full BIOS reset and only changed what’s needed, like Gen4 for M.2_1. Still stuck at Gen4 x2. What’s weird is my old SSD (kioxia) worked perfectly at x4 in the exact same setup, no tweaks needed… 🙁

 

[helpstar]

is the latest amd chipset driver installed?
https://www.amd.com/de/support/downloads/drivers.html/chipsets/am5/b650.html

do a BIOS reset by jumper and only change the boot order if needed, nothing else

install latest Samsung Magician software

try the non beta BIOS

might be a faulty motherboard or SSD

is your other SSD still working @x4?

 

[Akrad]

is the latest amd chipset driver installed?
https://www.amd.com/de/support/downloads/drivers.html/chipsets/am5/b650.html

do a BIOS reset by jumper and only change the boot order if needed, nothing else

install latest Samsung Magician software

try the non beta BIOS

might be a faulty motherboard or SSD

is your other SSD still working @x4?

Yeah, the latest AMD chipset drivers are installed.


I already reset the BIOS (not via jumper yet), only changed boot and M.2 settings.


Samsung Magician is fully up to date.


I’ll try flashing the non-beta BIOS, makes sense.





What’s weird is that as soon as I installed the new Samsung 990 Pro, it showed up in x2 mode.


My previous SSD (Kioxia Exceria G3 Plus) ran at x4 in the exact same slot and setup, without any BIOS tweaks.

 

[helpstar]

Why did you alter the M.2 settings?

Edit 01:
Try the M2_2 slot

Edit 02:
Try CrystalDiskInfo to have a look @ the speed

 

[Akrad]

Why did you alter the M.2 settings?

Edit 01:
Try the M2_2 slot

Edit 02:
Try CrystalDiskInfo to have a look @ the speed

I tried, but besides the second slot is a gen 3 I think. In short, it didn't change anything 😔 other ideas please

 

[evermorex76]

I tried, but besides the second slot is a gen 3 I think. In short, it didn't change anything 😔 other ideas please

You didn't answer, why are you altering the M.2 setting to force Gen4? Have you even TRIED to set it to Auto? And according to the manual, the M2_2 slot is also Gen4. Your CPU has 8 lanes for NVMe and both slots are connected to the CPU.

If it only works at x2 in both slots, then you may just have a bad drive. But...

Weirdly, another user here with an MSI board was also seeing his Gen3 drives for some reason only connecting at x2, even though a Gen4 drive connected at x4 in the same slot. They let MSI Center update drivers and that seemingly resolved the problem, at least until other drivers got updated.

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[Akrad]

You didn't answer, why are you altering the M.2 setting to force Gen4? Have you even TRIED to set it to Auto? And according to the manual, the M2_2 slot is also Gen4. Your CPU has 8 lanes for NVMe and both slots are connected to the CPU.

If it only works at x2 in both slots, then you may just have a bad drive. But...

Weirdly, another user here with an MSI board was also seeing his Gen3 drives for some reason only connecting at x2, even though a Gen4 drive connected at x4 in the same slot. They let MSI Center update drivers and that seemingly resolved the problem, at least until other drivers got updated.

I just wanted to try different settings to see if it would fix the SSD running at PCIe x2. Okay, I’ll try switching the SSD to another slot and see how it goes.





By the way, I thought MSI Center wasn’t great—kind of heavy and full of bloatware. What exactly are the important updates to apply through MSI Center to avoid this kind of issue?

 

[evermorex76]

By the way, I thought MSI Center wasn’t great—kind of heavy and full of bloatware. What exactly are the important updates to apply through MSI Center to avoid this kind of issue?

If you're going to use it, just let it update everything. I don't have an MSI board and have never looked at the app so I can't say what you might see available. The AMD B50 chipset and any CPU, PCIe, or NVMe drivers if any of those are listed separately would be the most important. All of those "driver update apps" are bloated and used for advertising, but at least with the one from the manufacturer it should be getting the right things for your board.