Samsung 980 pro SSD extremely slow when connected to CPU PCIe 4.0 4x NVME M.2 slot.

[linustechtipscom]

I have two 980 pro SSDs 500gb and 1tb. Both of them are extremely slow when connected to top M.2 slot (which is connected via CPU 4x PCIe 4.0 lanes). 

 

Both work as expected with very good results when connected to chipset m.2 slot or through cheap amazon PCIe adapter card. 

 

And here's 970 Evo plus connected to top M.2 slot (which is connected via CPU 4x PCIe 4.0 lanes). 

 

 

Specs:

CPU: Ryzen 5800x

motherboard: MSI x570 gaming plus. 

 

CrystalDiskInfo, hardware info and Samsung magician report the SSDs connected through 4x PCIe 4.0

 

Iv'e tested 4 SSDs (980 pro 500gb/1TB, 970 evo and P34A80 1 TB) in both m.2 slots and PCIe adaptor card (PCIE to m.2). The PCIe 3.0 SSDs works fine in both m.2 slots and PCIe adaptor card. PCIe 4.0 SSDs work fine in the bottom (chipset) m.2 slot and PCIe adaptor card. but both 980 pros slow down when plugged into top CPU m.2 slot.

Also my bottom 16x PCIe slot is connected to the chipset lanes and top is connected to CPU lanes. when the 980 Pros are plugged into PCIe adaptor card they work fine in either of the PCIE 16x slots.

I've updates to SSDs to latest firmware.

bios to latest firmware.

Updated chip set drivers.

forced installed Samsung NVME express drivers.

disconnected all SATA devices

disabled onboard LAN and audio devices. 

reseat the CPU twice.

 

please send help I'm trouble shooting this for three days straight. 

[Chris Pratt]

Bizarre. I can't think of anything that would explain that. You can get higher speeds on that slot with a Gen3 drive, and you get full speed when connected via an addin card. If there was something wrong with the slot, the Gen3 drive would be expected to have issues too and if there was something wrong with the drives, they'd have poor performance plugged into the addin card as well.

 

Real head scratcher. How long have you had the board? That still seems like the most likely candidate, so might be worth returning or RMAing it, just to rule it out, if nothing else. FWIW, the MSI X570 Gaming line of boards are known to be subpar, but most of the issues I've heard of centered around overheating and poor VRMs. Still, given there's known issues, it's not out of the realm of possibility that this is just one more.

[GuiltySpark_]

5 minutes ago, Chris Pratt said:

Bizarre.

I read through it, had some suggestions but then realized they did all the troubleshooting steps already that you would do here and it's still unexplained. 

 

Bizarre indeed. 

[linustechtipscom]

7 minutes ago, Chris Pratt said:

Bizarre. I can't think of anything that would explain that. You can get higher speeds on that slot with a Gen3 drive, and you get full speed when connected via an addin card. If there was something wrong with the slot, the Gen3 drive would be expected to have issues too and if there was something wrong with the drives, they'd have poor performance plugged into the addin card as well.

 

Real head scratcher. How long have you had the board? That still seems like the most likely candidate, so might be worth returning or RMAing it, just to rule it out, if nothing else. FWIW, the MSI X570 Gaming line of boards are known to be subpar, but most of the issues I've heard of centered around overheating and poor VRMs. Still, given there's known issues, it's not out of the realm of possibility that this is just one more.

had the board for quite a while bought it like November 2019. Had no issue with it what so ever. I've OC 3600x, 5800x, 3600mhz micron E, 3600mhz hynix C and 4400mhz Samsung b with really good results (3800mhz 14-8-16-13-27-288 at 1.53v).

 

Only explanation I have is poor connection between CPU pins responsible for PCIe lanes. OR pins in m.2 slot. Probably not good enough connection for higher frequency PCIe 4.0 link and that's why speeds are all over the place.    

[Tegneren]

Just to test, try setting the top m.2 slot to gen 3 in BIOS manually and test with the 980 Pro to see if you at least get gen3 speeds on it.

[Tegneren]

27 minutes ago, Tegneren said:

Just to test, try setting the top m.2 slot to gen 3 in BIOS manually and test with the 980 Pro to see if you at least get gen3 speeds on it.

Come to think of it. Try setting it manually to gen 4.0 also. Might be that if its on auto it sets it to gen 2.0 for some weird reason. PCIe x4 2.0 has a max transfer speed of 2 GB/s, so it fits.

[linustechtipscom]

I was thinking it was defaulting to 1x 4.0 lane didn't thought it could be setting to 2.0. How do I manually set PCIe speeds in bios, anyone here familiar with MSI clickbios 5?

[Tegneren]

26 minutes ago, linustechtipscom said:

I was thinking it was defaulting to 1x 4.0 lane didn't thought it could be setting to 2.0. How do I manually set PCIe speeds in bios, anyone here familiar with MSI clickbios 5?

If I'm not wrong its in Advanced mode under Settings->Advanced->PCI Subsystems->PCH Gen Switch

[linustechtipscom]

26 minutes ago, Tegneren said:

If I'm not wrong its in Advanced mode under Settings->Advanced->PCI Subsystems->PCH Gen Switch

there's no option to set m.2 slot to gen 3. CrystalDiskInfo, hardware info are still reporting PCIe 4.0

[Tw33die]

On 2/11/2022 at 4:24 PM, linustechtipscom said:

there's no option to set m.2 slot to gen 3. CrystalDiskInfo, hardware info are still reporting PCIe 4.0

 

Hey! Sorry to necro a bit but did you get this sorted? I'm having a similar issue where 1 of my Firecuda 530's is running at half the speed of the other, despite both being in PCIe 4.0 slots according to the BIOS.

 

Sounds like it might be a similar issue to yours? I'm not very experienced with this nor have I gone into the motherboard itself to move things around (it's a brand new computer) but I've checked the BIOS and stuff.

 

Any thoughts, seeing as you seem much cleverer than me!!

 

Cheers

Nick