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 mixed random I/O performance of the Samsung SSD 850 120GB is substantially slower than the old 850 EVO, but is slightly faster than the 750 EVO and well ahead of all the non-Samsung drives.

The 850 120GB isn't particularly consistent across the mixed random I/O test, and there isn't a strong trend to its performance. It is somewhat slower on the write-heavy half of the test. It is slower than the old 850 EVO in every phase of the test and doesn't significantly pick up the pace at the end when the workload is almost pure random writes, but neither does it suffer any severe performance drops.

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 drives are the four fastest drives on the mixed sequential workload test, with the 850 120GB coming in third place of the 120-128GB drives and only slightly faster than the 750 EVO. The 850 120GB is about 30% faster than the HP S700, the next fastest in-production model in this roundup.

The performance of the Samsung SSD 850 120GB drops significantly during the first half of the mixed sequential I/O test as the proportion of writes increases, but it stabilizes in the second half of the test. The other Samsung drives are the only ones that meaningfully outperform the 850 120GB at any point during the test,
but the 850 PRO is the only one that maintains a clear lead over the 850 120GB all the way through.

Sequential Performance Conclusion: It's a Good Option at 120GB
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  • Kristian Vättö - Monday, November 27, 2017 - link

    There are still MLC based enterprise SSDs from Samsung, such as SM863a.
  • yifu - Saturday, December 2, 2017 - link

    also Toshiba hk4r
  • qlum - Monday, November 27, 2017 - link

    For the pc's at work I always use 120gb ssd's as they offer enough capacity and are still about €20 cheaper then 200gb+ drives.
  • bug77 - Tuesday, November 28, 2017 - link

    I'm not sure giving up 80GB (40%) space to save €20 is the right choice. Remember, these things don't like being full and people tend to save a lot of junk of their drives.
    That said, the smallest SSD is still way better than the fastest HDD. (Have you ever seen Win10 trying to patch itself while installed on a HDD?)
  • ads295 - Tuesday, November 28, 2017 - link

    I think that's why laptops started skipping on the HDD activity LED from as early as when Win8 was available.
  • bcronce - Tuesday, November 28, 2017 - link

    Great for my firewall. I only need ~4GiB of space.
  • Glaurung - Tuesday, November 28, 2017 - link

    "Remember, these things don't like being full and people tend to save a lot of junk of their drives."

    For situations where the drive is never going to be full and you just need the cheapest possible SSD, it's fine. For instance, My spouse writes reports for a living, and she has never come anywhere near to filling up the 40gb X25-V on her work laptop. (no music, no pictures, no videos, just documents and PDFs and audio recordings that she refers to and then deletes when the report gets final client approval).
  • pixelstuff - Monday, November 27, 2017 - link

    We've been missing the 128GB 850 Pro model with it's 10 year warranty, which usually cost about $90. We were using it in single task devices such as DVRs with secondary data drives. Having to move to the 256GB 850 Pro just meant we had to spend an extra $30+ for no extra benefit, and unfortunately those 256GB drives never dropped to the $90 price range.
  • mapesdhs - Wednesday, November 29, 2017 - link

    Pricing did drop that low at one point; in the UK the 850 EVO 250GB was 53 UKP from Amazon and not much more elsewhere (meanwhile, 500GB pricing was slowly heading down to 100 UKP), but then after a blowout sale of several thousand 850 EVO 500GB units by one retailer in two weeks at around 115 UKP each (I bought two), I'm sure Samsung realised they simply didn't need to sell their tech so cheap, prices went up, and all the other vendors followed suit. Also, when new models came out, old models were almost immediately removed from seller sites, sometimes on the same day. Since then, pricing has almost doubled, there's just no need for the manufacturers to offer low pricing when they can easily sell everything they make due to OEM demand. It's ironic that the nature of that demand is largely by a consumer demographic that treats tech as thoroughly disposable, and often has little regard for what it is or how it works.

    The more I see new products like this being worse than old products, the more I'm impressed with what Intel has done with Optane, etc. At least Intel has actually done something new, whereas Samsung seems to have done what Intel did with its CPU-based strong position, ie. sat on its butt for several years while the cash rolled in and not bothered to innovate. Have to wonder why Samsung couldn't have brought ought something like Optane ages ago, and for the consumer market, not just Enterprise. Yes there's a shift towards NVMe, but it's not that big yet (with warranties 50% shorter and insane price hikes on retail versions), and a lot of consumers just want capacity with decent quality. At this point a 4TB SATA SSD with the quality level of the 850 EVO would sell very well if sensibly priced, but nobody's even trying, they're still having fun selling low capacity models (why sell one 4TB when one can make a lot more selling twenty 120GB units). I remember SanDisk promised to have an 8TB model by now, but that never happened.

    Billy, add the old 840 and 840 Pro into those results charts, I bet this new 850 wouldn't look so impressive, ditto if other old models were included too like the Vertex 4, Vector, Neutron GTX, etc. Heck, even the old 830 would likely put most of the modern non-Samsung models to shame (ditto something as ancient as a Vertex3, and it'd be hillarious too see where the budget Agility3/4 would fit in the charts today). SATA SSDs have become like CPUs before Ryzen finally launched, the tech has stagnated or even gone backwards. The 750 was touted as a cheaper 850 EVO, but in reality it became more expensive. I get that the nature of parallelism in NAND means larger dies don't offer the performance at lower capacities, but then that's why it would make sense to create something genuinely new; Intel needed a good poke in the ribs from Ryzen to get moving again with its CPU line, but at least it *did* something with respect to developing new storage tech.

    Ian.
  • WithoutWeakness - Monday, November 27, 2017 - link

    First section header in the introduction: The *Samung* SSD 850"

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