The Western Digital WD Black SN750 SSD Review: Why Fix What Isn't Broken?
by Billy Tallis on January 18, 2019 8:01 AM ESTAnandTech Storage Bench - Light
Our Light storage test has relatively more sequential accesses and lower queue depths than The Destroyer or the Heavy test, and it's by far the shortest test overall. It's based largely on applications that aren't highly dependent on storage performance, so this is a test more of application launch times and file load times. This test can be seen as the sum of all the little delays in daily usage, but with the idle times trimmed to 25ms it takes less than half an hour to run. Details of the Light test can be found here. As with the ATSB Heavy test, this test is run with the drive both freshly erased and empty, and after filling the drive with sequential writes.
The WD Black SN750 is a few percent faster overall than last year's model, allowing it to tie with the Phison E12-based Corsair MP510 on the Light test. But the Samsung 970 EVO and Silicon Motion SM2262EN-based drives are still substantially faster, at least when the test is run on an empty drive.
The average and 99th percentile latency scores for the SN750 are a few microseconds faster than its predecessor, which doesn't change the drive's rankings. The average latency scores are pretty close to the fastest drives, but the 99th percentile latency scores are merely average for this product segment.
The average write latency scores from the SN750 are virtually tied with the fastest drives, and the average read latency scores are imperceptibly slower than the Samsung 970 EVO.
As with average write latency, 99th percentile write latency for the SN750 is basically tied with the fastest drives—every write lands in the SLC cache with minimal delay, even when the test is run on a full drive. The 99th percentile read latencies do not rank as highly, but are still comfortably below 1ms even for the full-drive test run.
As with the Heavy test, the new WD Black leapfrogs the Toshiba XG6 to retake our record for most energy efficient NVMe SSD on the Light test. There's still a bit of catching up to be done before it matches the WD Blue SATA SSD, but it's still quite an accomplishment for the SN750 to use half the energy required by the Samsung 970 EVO.
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Oxford Guy - Monday, January 21, 2019 - link
It's weird to review minor products and not review something major like the GTX 960.It may be explainable without conspiracy but it's still weird, in terms of priorities.
Alistair - Friday, January 18, 2019 - link
Can't wait to read the SX8200 Pro review. I've bought a few, and I believe they are the best performing drives for the money right now. Excellent. I stopped buying Samsung after they started denying warranties in Canada (and they don't seem to want to fix that). Anyways the Samsung drives cost almost twice the SX8200 pro and perform exactly the same pretty much. Maybe the SX8200 Pro is even faster than the 970 EVO honestly.gglaw - Friday, January 18, 2019 - link
A few from decent reviewers are already up for this and the HP EX950 which are small upgrades over the incredibly well-rounded drives they replaced. The SX8200 (non-pro) and EX920 go on so many massive sales it is hard to beat them until the newer drives start dropping in price. The average home user would never know whether they had a 970 Pro, SX8200, SX8200 Pro, or EX950 running so major price differences would make the decision for me. After my initial experiences with the SX8200/EX920, these have been all I've stocked for close to a year. Made me almost regret my 970 Pro. They regularly go on sale for ~$75 for 500GB, and $135 for 1TB versions so my SSD adventures have become rather boring with no close 2nd place I would even consider buying.I'm likely going to get a SX8200 Pro just because I can't help myself with new versions of my favorite drives, but I'm already 99% positive I'll be in the same boat of not being able to tell any difference with the small upgrade. Then I'll have buyer's remorse again like the 970 Pro, knowing the 1TB version of the cheaper drive is barely more than the new 500GB one (SX8200 1TB $135, Pro 500GB $115).
ajp_anton - Friday, January 18, 2019 - link
What's wrong with WD's idle power consumption, and am I right assuming that that makes it unsuitable for laptops (mobile ones, not gaming)?Billy Tallis - Friday, January 18, 2019 - link
We test SSDs on a desktop, and that means we need to jump through some hoops to get PCIe power management enabled. I've never encountered a desktop motherboard that even has PCIe ASPM enabled by default, and when you are lucky enough to get a BIOS option to turn it on, you can't trust that to take care of everything. Even with the OS set to override the motherboard's settings, not all drives are able to enter their deepest sleep state on our testbed.I view this situation as being similar to DEVSLEEP for SATA drives. It's pretty likely that a laptop which was designed to use M.2 PCIe storage will have all the right firmware bits enabled to use the deepest power saving modes, but they're normally not used (or usable) on a desktop and I don't currently have equipment that can work around that.
hnlog - Saturday, January 19, 2019 - link
WD Black NVMe has problem on Linux with default parameter.Is it fixed on the new model?
https://community.wd.com/t/linux-support-for-wd-bl...
I think WD should test before shipping the former model.
Billy Tallis - Monday, January 21, 2019 - link
Basically every NVMe SSD vendor has shipped something that turned out to have serious power management bugs, most often with APST and only on certain host systems. It's pretty clear that no vendors (SSD or motherboard) are thoroughly testing those features before shipping, and instead just make sure that it works with a small handful of Windows configurations. But even the Windows NVMe driver is a moving target and new builds have caused problems.It would probably help if the UNH-IOL NVMe Integrator's List testing included APST, but their current test plan only checks whether the drive can handle manually setting power states. And even if they were more thorough, only a few vendors put consumer drives through that certification.
FXi - Sunday, January 20, 2019 - link
I wonder when we'll see the upper end of sizes in consumer drives jump to 4TB. Durability seems to be ready. Perhaps consumer need isn't quite there. But if controllers can handle it and layers exist for it to be built to that size in the M2 format, you'd think that's where they would go next since prices have come out of the stratosphere.eastcoast_pete - Sunday, January 20, 2019 - link
Is it just me, or do these comparisons make the HP 920 look quite good? Not in terms of top performance, but in performance/price. Has anybody here had any experiences with 920 drives?piasabird - Sunday, January 20, 2019 - link
Why not compare similar products together? Why is one drive a 2 TB drive? Since 2TB has more save locations it may naturally be faster due to drive space, cache size, energy usage, etc. Maybe Anandtech doesnt use samsung drives because Samsung will not donate the drives for free but other companies would give them free gear to test.