SN750 PCIe 3.0 4x but 5 GT/S only

Hi,

I installed a SN750 and it works but the speeds are a bit lower than I expected. On closer inspection, I found that the negotiated speed to the SN750 is only 5 GT/s of the available 8 GT/s (it is on PCIe 3.0 on 4x). Has anyone experienced something similar? Any suggestions on how I can force 8 GT/s?

Thanks!

You need to give us some more info to go on, like:

  1. What’s the make and model of your motherboard
  2. Do you use an M.2 to PCIe adapter card?
  3. Publish some benchmark test results (Crystal disk on Win, or fio on Linux (live)).
  4. What is the low level format of your SSD (512B or 4096B)?

Hi Marty,
Sure.

  1. Motherboard Model: GIGABYTE Z97P-D3
  2. Yes: https://www.amazon.co.uk/gp/product/B07RZZ3TJG
  3. See below
  4. See below

image

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I can’t add another screenshot but HWInfo is showing the Current Link Speed of 5 GTs vs Maximum Link Speed of 8 GTs for the device.

Those results are rather disappointing for such a highly spec’ed NVMe drive.

At first glance it doesn’t look like you’re running at PCIe 3.0 on 4x speeds, but rather at PCIe 2.0 4x speeds or maybe PCIe 3.0 2x …

The specs of your MB confirm my hunch.
The specs state that the PCIEX4 and PCI Express x1 slots conform to PCI Express 2.0 standard.

In which PCIe slot did you drop the M.2 to PCIe x4 card?
Unless you dropped it in the PCIEX16 slot (The PCIEX16 slot conforms to PCI Express 3.0 standard.), you’re running at PCIe 2 speeds. Then you might as well have bought a much lower spec’ed (and cheaper) NVMe drive.

If your PCIEX16 slot is unpopulated (with a video card), then drop it in there to enjoy the full power of your fast NVMe drive.

Thank you, well spotted. I assumed the x4 slot would also run at PCIe 3.0 which it apparently does not.