New NVME Running at HALF Speed - What could be the cause?

vgchat said:

The first thing that comes to mind is bios pcie settings. Check that yours are ok.

If the PCIe settings are the same for both M.2 slots, then it is fine as it is since the WD one is operating at full speed in the other slot. But if PCIe settings can be adjusted individually in BIOS then perhaps I accidentally changed something...though I think this is highly unlikely as I didn't save any changes when I did peak in the BIOS, and as mentioned previously the other drive in this slot was working top speed. I must have received a defective unit... should hear from Sabrent in a few hours.

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bobkn said:

A review of the drive: Sabrent Rocket NVMe 4TB PCIe Gen3.0 x4 M.2 SSD Review | TweakTown

Not sure that it's the exact drive, but it's 4TB and TLC. A benchmark:

Attachment 318638

This doesn't explain your issue, but there's clearly a problem.

As you've seen, Sabrent uses the Windows NVME drivers.

Yup, thats the exact model. Thank you

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Currently in troubleshooting mode with Sabrent... they asked if the Rocket's bus bandwitdth is setup to X2 or X4 mode..

So I took these screenshots and wanted to share here...
Kinda looks like it's operating at half mode? Because the one after is my WD NVME which is working at full speed...
Could it be?

That would definitely explain why you are seeing half the speed. If you are switching back and forth between these 2 drives and not changing anything in the BIOS, then it doesn't seem like a misconfiguration on your side.

If I understand properly the SN750 in the same slot is full speed, but when you put the new drive in there its connecting at half speed to the PCIE. That suggests a possible compatibility issue where the drive is perhaps misdetecting the capability of the slot.

ASUS had me update the BIOS. But upon restarting I was greeted by the American Megatrends screen advising that I need to run Setup (F1).. saying intel optane memory or the raid configuration was built and that i have to set the sata mode to RAID in order to avoid unknown issues. Not knowing why I was getting this screen or what to adjust, I called ASUS so they would tell me what I need to tweak.

I was told to ENABLE CSM... and save/exit. Got into Windows... was told to test speed again but it was still half. However, while I WAS in the BIOS I did see the option that Sabrent was telling me to look for - PCIe bandwidth and indeed it was set to 2X not 4. We did NOT change it yet - instead I was advised to try enabling CSM first, to at least get inside Windows.

I did notice that when I was about to change the X2 to X4 in the BIOS it did warn that SATA ports 5/6 would be disabled. Well, I don't know what those ports are connected to but the manual clearly states that bandwidth is only shared with socket M.2_1 which is NOT what the Sabrent is on.

So right now, as things stand, Sabrent seems to know where the issue is and what I need to manually tweak in the BIOS, but ASUS seems to have thrown me down a rabbit hole because I can't get into BIOS anymore since the CSM was enabled (there is no Logo screen with option to enter BIOS - I even repeatedly tapped DEL and F2 hoping to get in even if I couldnt see the logo screen displayed).

Do you have the Sabrent drive in M.2_1? According to the manual:

The M.2_1 socket shares bandwidth with SATA6G_2 port when using
M.2 SATA devices. Adjust BIOS settings to use a SATA device.

It's not obvious why this would be different than with the older NVME drive.

If you can't get into the BIOS, the obvious thing to try is clearing the CMOS. That's done with a jumper on your motherboard.

It looked like the Sabrent drive was not faulty and that it was just a matter of switching the speed of this PCIe from X2 to X4 but I now believe the drive is defective. Here's why:

The previous M.2 NVME drive operated at its full speed in this slot (3500MB) and since I didn't change anything in the BIOS, let's assume it was set to X2.

This is NOT a shared bandwidth port.

I have switched the bandwidth to X4 to troubleshoot...



Speed was the same problematic half speed...in fact one of the test was even lower and only 1100MB



Switching to X4 is said to disable SATA ports 5/6 - not what I want. Which is likely why I had it on X2 and was getting max speed from the WD NVME previously in that slot.

Having switched this to X4 not only did NOT give me the full speed of the Sabrent but it made my most important drive dissappear.



I don't know what ASUS can possibly tell me at this point. I can't think of any solution but to order a replacement.

orlando1974 said:

(snip)

This is NOT a shared bandwidth port.

(snip)

I have to admit that I'm not solid in my understanding of what a "shared bandwidth" port is. However, if the M.2 socket competes for PCI-E lanes with a SATA controller, that sounds like bandwidth sharing to me.

Check the available data rate of PCI-E 3.0 X2. If I understand it correctly, it's 2GB/s. That would limit the performance of the Sabrent drive. I don't understand how the prior SSD could have reached 3500MB/s sequential reads if the M.2 socket was limited to X2.

orlando1974 said:

Switching to X4 is said to disable SATA ports 5/6 - not what I want. Which is likely why I had it on X2 and was getting max speed from the WD NVME previously in that slot.
Having switched this to X4 not only did NOT give me the full speed of the Sabrent but it made my most important drive dissappear.

I don't know what ASUS can possibly tell me at this point. I can't think of any solution but to order a replacement.

Let's hope the replacement from Sabrent solves your issue.

Has anybody got experience of the Sabrent pcie 3 nvme disks? I might get one.

SIW2 said:

Let's hope the replacement from Sabrent solves your issue.

Has anybody got experience of the Sabrent pcie 3 nvme disks? I might get one.

I've used a couple of 1TB Sabrent drives. One was a 1TB QLC PCI-E 3.0 drive. The other was a 1TB TLC PCI-E 4.0 one. Both performed as expected.