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 Samsung 970 EVO is slightly slower than the OEM PM981 on the mixed random I/O test, but that still leaves the 1TB model very near the top of the chart, and the 500GB 970 EVO is only slightly behind the MLC-based 960 PRO.

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

The power efficiency of the Samsung 970 EVO trails the PM981 by a larger margin than performance alone did. The efficiency of the best MLC drives seems almost out of reach for TLC drives, except that the WD Black is in third place overall with 26% better efficiency than the 970 EVO.

The Samsung 970 EVO's performance barely drops when writes are first added to the mix, and it grows at an accelerating rate through the rest of the test. The PM981 pulls ahead in the final phases with higher random write performance than the 970 EVO. The 960 EVO showed very flat performance until fairly late in the test, leaving it well behind the 970 EVO for overall performance despite offering similar performance at either end of the test.

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 Samsung 970 EVO sets new records on the mixed sequential I/O test, with the 1TB model beating the Intel Optane SSD and the WD Black. The 500GB model is significantly slower, but still performs well for its capacity. Both models are much faster than the PM981.

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

The 1TB Samsung 970 EVO is essentially tied for second place in power efficiency on the mixed sequential I/O test, but the first place WD Black has a large lead. The improved performance of the 970 EVO over the PM981 is match by improved efficiency, but in absolute terms the 970 EVO is drawing more power than almost any flash-based SSD on this test.

The performance of the Samsung 970 EVO on the mixed sequential I/O test wobbles around with an unusual pattern that mirrors that of the PM981 but little else. The 1TB 970 EVO shows the typical spike in performance at the end when the workload shifts to fully cacheable writes, but the test fulls the SLC write cache on the 500GB model and prevents it from getting that boost.

Sequential Performance Power Management
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  • mapesdhs - Sunday, May 6, 2018 - link

    HollyDOL, as others have said, it very much depends on what you're doing. As a C-drive it simply helps to have any kind of SSD at all rather than a rust spinner (except of course the cheap junk knockoffs like Gloway). The Vertex3 was a pretty good SSD for its time (I have lots of them), though back then the Vertex4 presented its own significant bump up in benchmark performance, as did the Vector. For general use, you might notice some difference compared to an NVMe device, certainly in bootup times, but beyond that it depends on the task. Some games will certainly load a lot quicker, assuming the CPU/RAM are able to take advantage of it. And btw, some older mbds can have a mod BIOS installed to enable booting from NVMe (I'm more familiar with the options for ASUS boards in this regard), and certain NVMe SSDs even have their own boot ROM (eg. 950 Pro) such that native boot support isn't required.

    It's a good idea for video editing though, eg. the main cache/scratch drive for After Effects or Vegas.
  • Lolimaster - Tuesday, April 24, 2018 - link

    Unless you work moving huge chunks of data (editing 4k for example) a lot there's no point going NVME over the Crucial MX500 sata.
  • Death666Angel - Tuesday, April 24, 2018 - link

    Especially in cramped cases, small form factor stuff, the gum stick is really nice because you don't need annoying cables around. My next MoBo will be some Ryzen thing in mATX with 2 M.2 slots (likely PCIe and SATA), so I can go all SSD for my desktop without any cables. I haven't noticed improvements after going to SATA3 SSDs from my Vertex/Agility first gen ones.
  • iwod - Saturday, April 28, 2018 - link

    I can't disagree more. SATA is limited in Seq speed. And it is actually a user observable difference in everyday use, between a 1.5 - 2GB/s and 600MB/s speed.

    Now whether that is worth a little more money you paid for is a different question.
  • peevee - Monday, April 30, 2018 - link

    And how you are going to hit the seq speed in real life? All external (USB or network) sources and targets are slower. Writing does not matter with write-back OS caching. Reading a document into memory is limited by memory size and actually parsing/decompression of the document. Unless you are copying huge files between RAM drives and your SSD, you have no use case. That is why the tests are generating random data on the fly, like NOTHING does in real life. And that is why sites like AT have NO reproducible real-life tests (like compilation of a large software package for example, or recoding of video), as they would show about 0 real difference between drives 2x in price.
  • mapesdhs - Sunday, May 6, 2018 - link

    I see a nice difference when cloning my photo/video archive (1TB SM961), moving files around, network access, etc., to the extent I'm now looking into 10GigE.
  • Lolimaster - Tuesday, April 24, 2018 - link

    You don't see everyday benefits because the things that make SSD's faster than HDD's (access times, random 4k QD1 reads) barely improves from sata to nvme. Even with an optane SSD you won't see much improvement.
  • Lolimaster - Tuesday, April 24, 2018 - link

    1-SSD had 100x less access time vs HDD and 100x higher 4k random performance, NVME basically only improves on sustained transfer raters.

    Going from 5-10ms to 0.07ms and from 400KB/s to 40MB/s~ was a lot.
  • Cooe - Tuesday, April 24, 2018 - link

    Yup. Without a doubt a good NVMe is much snappier, but you have to be the right kind of PC user for the difference to be that level of obvious. Even the heaviest applications, projects, etc... open instantly or near it vs the usual couple seconds, up to a minute or so for the really beefy crap with SATA-III, so if you're well familiar with PC's & in-tune with yours' level of performance, and are somebody who's regularly booting up, closing, and switching between multiple applications, storage heavy projects, etc... NVMe provides an obviously superior experience. And even if you aren't that kind of person yet, if you have compatible hardware the price gap has shrunk enough that I'd still recommend NVMe over SATA regardless as storage loads only ever increase with time. Aka you might not be the kind of person/PC user that can/will notice it now, but in a few years chances are that you most definitely will, and'll be glad you made the choice you did.

    For most lighter users atm otoh, SATA-III's already plenty fast enough for the workloads they regularly do. And that's on top of the fact that they simply don't have the level of "PC awareness" for the difference to stand out the way it does for heavy users and PC nerds like myself. And of course, even for us heavy users & multi-taskers who get real & significant benefits from the switch, it's still nothing on the order of the HDD to SATA SSD jump which is why those not well aware of their PC's current performance level and whom aren't heavy storage users (lots of regular & concurrent file access, movement, and modification) are rather likely to not notice the improvements w/o having them explictly pointed out (ala instantaneous or near it launches of most apps, even for multiples simultaneously vs delay's of a handful of seconds to a minute+ or so for the biggies, vastly improved file copy & movement speeds, ability to maintain SATA SSD levels of responsiveness while heavy storage workload(s) are active in the background, etc...)
  • Cliff34 - Tuesday, April 24, 2018 - link

    For me, the higher premium prices for nvm ssd vs sata ssd is not worth for the performance gain. I'm sure a nvm ssd is faster but I don't want to shell out few hundreds dollars (comparing the 1td) more to have my computer a few seconds faster.

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