AnandTech 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.

ATSB - Light (Data Rate)

The WD Black's average data rates on the Light test are slightly slower than the Samsung 960 EVO when the test is run on an empty drive, and a bit faster when the drive is full. The Samsung PM981 is the only drive that has a clear lead in both cases, and even then it isn't a very big margin. The worst-case performance here from the new WD Black is substantially faster than the best-case from last year's WD Black.

ATSB - Light (Average Latency)ATSB - Light (99th Percentile Latency)

The average latencies from the WD Black during the Light test are as low as any SSD offers. The 99th percentile latencies are not quite as fast as Samsung's best drives offer, except that the full-drive performance is better than the 960 EVO.

ATSB - Light (Average Read Latency)ATSB - Light (Average Write Latency)

There are quite a few SSDs with average read latency scores that are close to or slightly better than the WD Black, and even the low-end NVMe SSDs keep the average read latency down to a fraction of a millisecond on the Light test. The average write latencies from the WD Black are essentially tied for first place with Samsung's drives.

ATSB - Light (99th Percentile Read Latency)ATSB - Light (99th Percentile Write Latency)The WD Black offers great 99th percentile write latency on the Light test as its SLC cache never fills. The 99th percentile read latency doesn't rank quite as high, but the full-drive score is very good.

ATSB - Light (Power)

As with the Heavy test, the only NVMe SSD we've tested that can match the WD Black's power efficiency is the Toshiba XG5. These drives get the job done much faster than a SATA drive without using any more energy.

AnandTech Storage Bench - Heavy Random Performance
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  • Cooe - Friday, April 6, 2018 - link

    This is why the 250GB 960 EVO (and inevitably for the new WD Black as well) is far and away the most popular SKU just about everywhere. At around $110-120 vs $80-90, you're only paying a premium of around 20-25% over an equivalent tiered SATA III drive (ala an 850/860 EVO), though yes, you are sacrificing your sequential write speeds past the 13GB Turbowrite cache to just 300MB/s to get that comparatively tiny price premium for good NVMe vs SATA-III ratio.

    Tbh though in most general consumer PC workloads the above simply isn't an issue, as sustained writes of >13GB are few & far between, and the cache turnover speed while idling is speedy quick. I think this is exactly the reason why Western Digital & SanDisk adopted the kind of handicapped nCache 2.0 into a very Turbowrite-esque system with nCache 3.0 (but more like 850 EVO's simplier static TW cache just a lot bigger, rather a dynamic one like the 960 EVO uses).
  • Dragonstongue - Thursday, April 5, 2018 - link

    competition is good, but not if they all want to keep pricing within a few $ of each other IMO.

    for nvme/M.2 drives they need to make sure is more universal that it is more plug and play so consumers can be assured it will work on their motherboard as a bootable OS drive right off the bat without driver specific support (quite a few drives quite a few no matter on Intel or AMD chipset seem to have this issue hence they need more plug and play support)

    costs more than a normal sata based one (performance is much higher though that does not always mean can see this difference) but having to screw around making the bios/windows able to use the drive in question sucks (not saying this is a problem with this specific model, but it is a problem)

    nice write up though ^.^
  • PeachNCream - Thursday, April 5, 2018 - link

    I agree with you on pricing. It would be good if WD had priced their drive a bit lower in order to force Samsung to respond since they have a competitive product, but they have to get a return on development costs so it's safe for them to match Samsung's price. I don't like it because the consumer isn't realizing a benefit in additional competition if neither company budges on cost, but I can understand the business justifications that are probably behind it.
  • Cliff34 - Thursday, April 5, 2018 - link

    What I do wish is that the m2 sata drives should be the same price as sata ssd. After all, the specs are the same just diff forms. Too bad for us consumers.
  • The_Assimilator - Friday, April 6, 2018 - link

    M.2 SATA drives should cost *less* than their 2.5" equivalents, and the 2.5" drives should simply be an M.2 drives in an enclosure with an M.2-to-SATA connector.
  • Cliff34 - Saturday, April 7, 2018 - link

    It should but it doesn't. My guess is because m2 form is a niche market because most computer accept SATA. Therefore, companies can charge more because they can get away with it. Unless there's a huge swing of adoption of m2 form for desktop and laptops, m2 will always cost more than SATA.
  • zodiacfml - Friday, April 6, 2018 - link

    True.
  • wr3zzz - Thursday, April 5, 2018 - link

    WD's pricing strategy is probably indicative that current demand for NVMe is still outpacing supply.
  • Arbie - Thursday, April 5, 2018 - link

    Great article and follow-up analysis of the tests; thanks.
  • iwod - Thursday, April 5, 2018 - link

    What are the difference in real world usage? We thought we needed better QD1, and even that doesn't return any significant difference in optane.

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