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

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.

seem quite reasonably priced atm
Sabrent Rocket Q 1TB NVMe SSD M.2 review - Introduction

orlando1974 said:

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...

Attachment 318736

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

Attachment 318737

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.

Attachment 318738

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.

That bios settings looks like you adjusted a 16 lane pci express slot, not the m.2 slot. Usually m.2 slot speeds are not adjustable in the bios.

Hey guys... major update...

I had ordered a replacement Sabrent Rocket 4TB after pretty much exhausting all troubleshooting steps with the manufacturer who was really baffled and up til the very end maintained that it was unlikely defective.

But I ended up canceling the return after I got positive results from swapping M.2 slots with the other NVMe in my system (WD SN750). For some reason, the WD Black SN750 is capable of delivering full speeds no matter what slot I put it in. HWinfo64 confirms that it is operating at X4 in both slots and CrystalDisk benchmarks also confirm max speeds in both M.2_1 and M.2_2 slots.

However, the Sabrent Rocket NVMe is ONLY capable of delivering on specs when inserted in M.2_1 slot. When used in M.2_2, it only works at half speed and HWinfo64 showed X2 regardless of the PCIe bandwidth being set to X2 or X4 in BIOS. CrystalDisk and proprietary Sabrent Control Panel would show speeds of 1700MB, half of what they should be.

But once I swapped them, both drives were showing X4 in HWinfo64, and both operating around 3400MB/sec.
The WD is slighter faster in terms of numbers - it reaches its marketed specs and actually exceeds them a bit.
The Sabrent scores slightly below marketed 3400MB specs, but I'm not mad. Still dang fast!

Would I buy Sabrent again? Not sure. I wasted 2 days on this and neither Asus nor Sabrent were able to figure it out. Why is the WD drive able to handle either slot and the Sabrent only one of them? Can this be fixed with a firmware update? Sounds like this one really needs to go in both of these companies knowledgebase as a known issue.

Sabrent in M.2_1 (top slot on Asus Prime Z390-A):



Sabrent in M.2_2 (bottom slot on Asus Prime Z390-A):

Thanks alot Ed for the additional insight!
I def don't have the budget or the inclination to perform the additional test you suggested but who knows, maybe someone down the road will find this thread and be able to chime in with an x4 PCIe!

For now I'm just going to enjoy the speed differences between 7200RPM and NVMe! :)

Yeah it does seem like a compatibility issue, whether you put the blame on the board or drive vendor no idea. But the main thing it works.

The kinda pathetic reply I got from ASUS... I mean, does it really add any information that I didn't provide them with? lol

I am writing this email as an update regarding your recent escalated case. In accordance with your escalation:



THe Sabrent Rocket 4TB NVME, is not compatible due to the fact the M.2 slot works with WD NVME full speed

orlando1974 said:

But once I swapped them, both drives were showing X4 in HWinfo64, and both operating around 3400MB/sec.
The WD is slighter faster in terms of numbers - it reaches its marketed specs and actually exceeds them a bit.
The Sabrent scores slightly below marketed 3400MB specs, but I'm not mad. Still dang fast!

It's good to hear that you found a solution that will work. The slight differences in #'s will never be noticeable on anything other than a benchmark utility.....guaranteed.

Can someone please explain clearly what Sabrent was trying to tell me here?
It's got me worried that I might run into issues when the time comes to upgrade my graphics card from GTX760 to an RTX2070?

Consider the fact that your motherboard works with 16X PCIe lanes if you have a Graphics card + 2X NVMe drives that is 12 lanes in use in case the graphics card consumes 4 lanes only.

orlando1974 said:

Can someone please explain clearly what Sabrent was trying to tell me here?
It's got me worried that I might run into issues when the time comes to upgrade my graphics card from GTX760 to an RTX2070?

Consider the fact that your motherboard works with 16X PCIe lanes if you have a Graphics card + 2X NVMe drives that is 12 lanes in use in case the graphics card consumes 4 lanes only.

I'm out of my depth here, but the i7-9700K provides 16 PCI-E lanes. The Z390 chipset provides 24, but they are limited to X4 maximum.

The first couple of posts here: PCIe lanes for the Z370 and Z390. Enough for my setup? : intel suggests that using two NVME SSDs will reduce their bandwidth, but that's obviously at odds with your experience.

If the M.2 slots get their PCI-E lanes from the CPU, then you still ought to be able to get two X4 for the M.2 and X8 for the GPU. (This assumes that none of the CPU lanes are reserved for any other purpose). X8 is supposed to not bottleneck any GPU with PCI-E 3.0.

Incidentally, why not an RTX 3070, if they ever become available at anything close to MSRP? There is supposed to be a good performance jump between the 2000 and 3000 series cards at the same level. UserBenchmark: Nvidia RTX 2070 vs 3070