Mixed Random Performance

Our test of mixed random reads and writes covers mixes varying from pure reads to pure writes at 10% increments. Each mix is tested for up to 1 minute or 32GB of data transferred. The test is conducted with a queue depth of 4, and is limited to a 64GB span of the drive. In between each mix, the drive is given idle time of up to one minute so that the overall duty cycle is 50%.

Mixed 4kB Random Read/Write

The 1TB Samsung 970 EVO Plus slightly improves on its predecessor's performance on the mixed random IO test, to widen Samsung's lead over other TLC-based drives. The 250GB model fares reasonably well, but is again no match for the oversized SLC cache on the 240GB ADATA SX8200.

Sustained 4kB Mixed Random Read/Write (Power Efficiency)
Power Efficiency in MB/s/W Average Power in W

The WD Black SN750 holds on to another power efficiency win and the Samsung 860 EVO SATA SSD is more or less tied with the 1TB 970 EVO Plus. Most of the 250GB-class drives have substantially lower power efficiency scores due to spending much more time working with a full SLC cache.

The 1TB 970 EVO Plus steadily picks up speed as the workload shifts to be more write heavy. The smaller 250GB model's performance flattens out during the middle half of the test as its smaller SLC write cache starts to get in the way, but toward the very end it too speeds up.

Mixed Sequential Performance

Our test of mixed sequential reads and writes differs from the mixed random I/O test by performing 128kB sequential accesses rather than 4kB accesses at random locations, and the sequential test is conducted at queue depth 1. The range of mixes tested is the same, and the timing and limits on data transfers are also the same as above.

Mixed 128kB Sequential Read/Write

The 970 EVO Plus is a bit faster than the original 970 EVO on the mixed sequential IO test, breaking Samsung's own record. The 250GB model finishes ahead of even the 240GB ADATA SX8200  and is only a few percent slower overall than the 1TB HP EX920.

Sustained 128kB Mixed Sequential Read/Write (Power Efficiency)
Power Efficiency in MB/s/W Average Power in W

The WD Black SN750 and Corsair Force MP510 have the top two power efficiency scores on the mixed sequential IO test, but the Samsung 970 EVO Plus and original 970 EVO are next in line. Both capacities of the 970 EVO Plus require more power than most of their competition, but they put it to good use.

The key to the high overall performance scores from the 970 EVO Plus seems to be that the Samsung drives do not lose performance as quickly when writes are first added to the workload. Many drives have pretty good pure read speed but at 90% or 80% reads they may be only half as fast, while the Samsung 970 EVOs don't see a steep performance drop until around the middle of the test.

Sequential Performance Power Management
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  • Chaitanya - Tuesday, January 22, 2019 - link

    Quite a minor upgrade over previous drive.
  • jeremyshaw - Tuesday, January 22, 2019 - link

    Hence the name.
  • Billy Tallis - Tuesday, January 22, 2019 - link

    More substantial than the WD Black SN750.

    I don't think we'll see any more big jumps until PCIe 4.0 ships. Pretty much everybody has caught up on the NAND side, and most of the controller vendors have had decent NVMe controllers out for a while. There's no low-hanging fruit like there was when companies were still trying to make SM2260 or Phison E7 compete against Samsung with inferior NAND.
  • DanNeely - Tuesday, January 22, 2019 - link

    More to the point it is a consistent incremental improvement. There've been far too many cases over the years when a v.next drive was an incremental improvement in manufacturing cost, that regressed in most to all performance numbers.
  • boozed - Tuesday, January 22, 2019 - link

    I call those performance improvements significant (just).
  • Flunk - Thursday, January 24, 2019 - link

    I don't think it's enough to elevate this drive over the high-end Silicon Motion drives in real-world uses. Not for consumers at least.
  • nectrone - Thursday, January 24, 2019 - link

    96-layer nand is an improvement on production speed, yields, and manufacturing cost, rather than perf. And tbh, we don't need better perf at all, or maybe a bit in 4k random, because 150MBps is a bit low in 2019. Instead, what we need, is prices to drop, below twice the price of an hdd of the same capacity.
    In 2018, 1TB tlc nvme 64-layer ssd was 10 times the price of an hdd, now in Jan it's 5 times. Sata 64-layer ssd were 7 times the price of hdd, now it's 3. I'd like TLC nvme to cost twice an hdd, and sata tlc to be the same price as an hdd. With 96-layer, we'll get closer to that.
  • haukionkannel - Tuesday, January 22, 2019 - link

    Pity that the consumer version does not get 4.0 this year... I was hoping to have 4.0 compatible ssd when AMD 570x boards comes out. Well most like with my usage even these Are fast enough and I am not going to be Bottle negged by 3.0.
  • sorten - Wednesday, January 23, 2019 - link

    I had the same reaction. I'm running an old gaming PC and I'm ready to switch to AMD with a full set of upgrades at the end of the year and was hoping for PCIE 4.0, but my SSD is so old that I know any drive will be a huge improvement.
  • ikjadoon - Tuesday, January 22, 2019 - link

    Meta: has the scrolling video ad been moved to the right? It finally doesn't cover up the article when you scroll. Huge thank you.

    970 EVO Plus: I'm excited for this to get added to the SSD 2018 Bench. Curious how close it matches the 970 PRO 512GB, now at $170. My almost-full 250GB 960 EVO needs a capacity increase and $40 isn't a big difference for a minimum two-year purchase.

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