Sequential Read Performance

For full details of how we conduct our Iometer tests, please refer to this article.

Iometer - 128KB Sequential Read

In sequential read performance the SM951 NVMe is stronger than the SSD 750, but it's actually outperformed by the AHCI version. Given that the performance doesn't scale at all and doesn't reach the stated 2,200MB/s, I suspect there is some thermal throttling going on, which are not present in the SSD 750 and SM951 AHCI with heat sinks.

Samsung SM951 NVMe
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Sequential Write Performance

Iometer - 128KB Sequential Write

The same throttling issue appears to be present in sequential write test where the SSD 750 is faster thanks to being able to scale performance with queue depth, whereas with the SM951 performance actually declines due to throttling.

Samsung SM951 NVMe
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Random Performance Mixed Read/Write Performance
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  • bill.rookard - Thursday, June 25, 2015 - link

    CentOS (Actually, RH6.5 and newer) are supposed to have in the box storage drivers for NVME. It apparently doesn't follow the same naming convention (/dev/sdx) since it doesn't utilize the SCSI protocols, but the NVME protocols.

    So - to check before you buy?

    #modinfo nvme - should list if your kernel has built in nvme support.

    if you have a drive in, check if an nvme drive is in there and is recognized

    #lspci | grep nvme
  • SofS - Thursday, June 25, 2015 - link

    Indeed, but my point was about their quality and how they compare between each other.
  • der - Thursday, June 25, 2015 - link

    10th comment!
  • bernstein - Thursday, June 25, 2015 - link

    i guess the 1tb 840 msata had either too slim margins or wasn't popular enough...
    still waiting for a 1tb M2 NVMe drive...
  • foxtrot1_1 - Thursday, June 25, 2015 - link

    See you in December 2016, then.
  • bernstein - Friday, June 26, 2015 - link

    obviously i was wrong since there also is an 1tb msata 850 evo.... now i am very curious as to why samsung doesn't have a 1tb M2 ssd!!!
  • Kristian Vättö - Friday, June 26, 2015 - link

    Because all the PCIe drives use MLC NAND, which is a lower capacity die.
  • kspirit - Thursday, June 25, 2015 - link

    The connector looks the same as that on the old SATA SSDs found in most laptops. I've got a 2280 sized Intel 1500 SSD in my HP Folio (Haswell). Would this give me PCIe speeds?
  • foxtrot1_1 - Thursday, June 25, 2015 - link

    No.
  • Metaluna - Thursday, June 25, 2015 - link

    Depends on whether HP hooked up the PCIe lanes on their M.2 connector, which I wouldn't assume without checking into it. The BIOS also needs to have NVMe support. In the most common configurations (i.e. the "B" and "M" keyings), M.2 is required to carry both SATA and 2-4 PCIe lanes, but some motherboard vendors routinely violate this and leave out one or the other. Asus drops the SATA on some of their higher-end Z97 motherboards, for example, so you can't rule out that someone else may have made the opposite tradeoff.

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