Lexar NM620 1TB NVMe SSD Review A Spectacular Fail


SPECworkstation 3.0.2 Storage Benchmark

SPECworkstation benchmark is an excellent benchmark to test systems using workstation-type workloads. In this test, we only ran the Storage component, which is fifteen separate tests.

Lexar NM620 1TB SPECws
Lexar NM620 1TB SPECws
Lexar NM620 1TB SPECws Chart
Lexar NM620 1TB SPECws Chart

SPECworkstation performance for the Lexar NM620 1TB is embarrassing. In both Product Development and Life Sciences, the NM620 manages to return the very lowest scores I have personally witnessed by a wide margin. The other disciplines are not quite as bad off, but nowhere does the drive approach the descriptor of ‘good’ in terms of performance.

Sustained Write Performance

This is not necessarily a benchmark, so much as trying to catch the post-cache write speed of the drive. While I am filling the drive with data to the 85% mark with 10 simultaneous write threads, I monitor the drive for the write performance to dip to the lowest steady point and grab a screenshot.

Lexar NM620 1TB Post Cache Write Speed
Lexar NM620 1TB Post Cache Write Speed
Lexar NM620 1TB Post Cache Write Speed Chart
Lexar NM620 1TB Post Cache Write Speed Chart

Keeping consistent with the rest of this review, the Lexar NM620 has terrible sustained write speeds. I estimated 30 MB/s for the fast majority of the time while filling the drive, dips below 20 MB/s were also quite common. Also, keep in mind, this measurement is taken when the drive is brand new; performance could potentially be worse if the drive is overly full or GC/ TRIM has not been run recently.


We monitored the idle and maximum temperature during testing with HWMonitor to get some idea of the thermal performance and requirements of the drive. Please keep in mind that our test bench is an open frame chassis in a 22C room, but with no direct airflow. As a result, this is not representative of a cramped low airflow case and is instead intended to model temperatures of a drive ‘on its own’.

Lexar NM620 1TB Temps
Lexar NM620 1TB Temps

Despite the objectively bad performance, thermals on the Lexar NM620 1TB still managed a somewhat toasty 70C during load.

Again, we are mostly looking for the absence of runaway thermals here during our testing rather than comparing drives to each other.

Final Words

The Lexar NM620 1TB is $120 on Amazon and Newegg right now, which is wildly overpriced for the performance you receive. For $120 you could buy a Samsung 980 1TB, or a WD SN550 1TB for $110, either of which is significantly faster.

Lexar NM620 1TB Front
Lexar NM620 1TB Front

As I mentioned earlier in my review, my first point of judgment when reviewing any product is whether it matches its own advertising, and the Lexar NM620 fails completely on that front. This is not “next-level performance for intensive workloads” and it is nowhere near achieving the claimed sequential performance levels. Perhaps it should be “next-level below performance for intensive workloads” instead.

This is a poorly performing drive that costs more than its competitors. You should not buy it.

Design & Aesthetics
Feature Set
Previous articlepfSense CE 2.5.2 Released with Updates
Next articleInspur NF5488A5 8x NVIDIA A100 HGX Platform Review
Will has worked in both big enterprise and small business IT since 2001. As a perpetual dabbler, he is always open to new solutions for old problems. That said, his personal IT motto has to be "if it's not broke, don't fix it" so sometimes the old ways are best


  1. Out of curiosity, do we know if this thing is based on some bottom-of-barrel NAND and, while clearly overpriced, doing a decent job of salvaging the situation given what it’s working with; or did Lexar manage to squander some perfectly decent flash chips by handicapping them at the controller?

  2. fuzzyfuzzyfungus,
    I just peeled back the sticker, the NAND is Micron 96L TLC, same as used on a number of very nice PCIe 4.0 NVMe SSDs. I would wager it is the controller holding this whole setup back, but I have almost zero insight into the controller itself since none of my customary utilities can interrogate it.

  3. So is it now necessary for serious review sites to figure out how to approximate some validation of flash endurance specs?
    And although the NAND in use here is Micron, I trust everyone is aware that Lexar hasn’t been a Micron brand for nearly 4 years now.

  4. Bob Niland,
    I have actually considered writing to drives until they die as an endurance test. However, the logistics of time almost always prevent that from happening. In this drive’s specific case, thanks to the abysmal post-cache write speed it would take 230+ days of continuous writing to reach the rated endurance level, and even on a much faster drive like the Samsung 980 you are looking at amounts of time measured in weeks instead of days. To me, the endurance rating is more like a facet of the warranty; it’s the mileage counter on your car- it exists to limit the warranty, not to enhance it.

  5. Thanks for checking on the NAND. That is not a good sign for their controller and/or firmware.

    A design focused on scraping adequacy out of really awful flash could actually be an interesting and legitimate contender(not as a direct substitute for high performance SSDs; but of interest for less performance critical bulk storage, or in applications that just don’t mechanically or electrically support HDDs); but kneecapping a TB of actually good flash by chasing some NIH internal design rather than being willing to throw Phison or similar a few bucks is just bad.

  6. It’s very well possible the drive is throttling. At 70 degrees it is probably reducing clocks or write operations to keep within thermal budget. The 980 pro and other nvme drives have a heatsink or heatspreader sticker that helps keep them cool.

  7. Mark,
    It is possible the drive is throttling during the initial load when it hit the 70C temp, but not during the rest of benchmarking as the drive was allowed to cool a bit prior to benchmarking. Also, the drive *began* writing at around 850 MB/s, it is not like it had a brief burst at 3300 MB/s and then slowed down, it *started* slow.

  8. Will: …230+ days of continuous writing to reach the rated endurance level…
    I hadn’t run the numbers, but that is not at all surprising, and in this case being a deliberate design decision must be pondered. Even on credible brands, in addition to time, you’re testing to destruction, and tying up some computer. Might be worth a look once in a while.

    On another enthusiast site this week, who list Lexar as a Partner, they ‘tested’ a Lexar SATA SSD in a glowing review …
    … that benched it against an HDD.
    Preserved that ad revenue, I suppose.

  9. Mark,
    You got me *just* paranoid enough about thermal throttling that I re-installed this drive and ran the CDM benchmark again. At no point in the test did the drive pass 62C – I monitored it the entire time – and the results were within the normal run-to-run variance and nearly identical to the results in the review. Also prior to publishing I had done a cursory check on the internet to see what other reviewers found, and over on Storagereview they had an equally terrible result with the drive, so I do not think it is just me!

  10. In my opinion a spectacular fail would be data loss. Do any of these tests actually check the integrity of the data?

  11. Will,
    Thanks for the thorough follow-up! I remembered some ssd’s did have this issue (Samsung 950 pro I believe). Okay clear conclusion then: it’s just a shitty ssd and no amount of cooling will improve the situation. 🙂

  12. Just as an FYI…

    A guy ran a SSD endurance test on a Sheiknak 120GB SSD and it went about 320TB before completely dying after 3 months. A 256GB BX500 went over 1PB before it died after a year. They found that the longer you write on it, the slower it starts to get.

    The Flash is not going to give out on 99.999% of these things before something else goes out like your patience.



Please enter your comment!
Please enter your name here

This site uses Akismet to reduce spam. Learn how your comment data is processed.