Endurance: Close to Planar MLC NAND

The big question with every new NAND generation is the endurance. We already saw 6,000 P/E cycles in the SSD 850 Pro and an amazing 40,000 P/E cycles in the SSD 845DC Pro, which proved that V-NAND provides substantially better endurance over today's planar NAND nodes. However, endurance was never really an issue with planar MLC NAND except in the enterprise space, so the 850 EVO with its TLC V-NAND offers a much more interesting insight to the capability of 3D NAND technology.

To test endurance, I put the 120GB 850 EVO through our usual endurance test suite. Basically I just used Iometer to write 128KB sequential data at queue depth of 1 to the drive while monitoring the Wear Leveling Count (WLC) and Total LBAs Written SMART values. The 'Current Value' of the WLC SMART value gives the remaining endurance as a percentage (starts from 99), whereas the 'Raw Data' value indicates the number of consumed P/E cycles. In order to estimate the endurance, I had to find the spot where the increase in 'Raw Data' value decreases the 'Current Value' by one.

Samsung SSD 850 EVO Endurance
Change in Current Wear Leveling Count Value 6
Change in Raw Wear Leveling Count Value 128
Total Data Written 15,260GiB
Estimated Total Write Endurance 254,325GiB
Observed Number of P/E Cycles 1,987

It appears that TLC flavor of V-NAND is rated at about 2,000 P/E cycles. The raw WLC value seems to be based on the user capacity (i.e. 120GB = 1 P/E cycle) because just going by it puts the endurance at ~2,133 P/E cycles (128/0.06), but that doesn't add up with the raw NAND capacity and total data written. However, the estimated total write endurance (which is just 15,260/0.06) suggests that the NAND itself is rated at 2,000 P/E cycles, which would make sense as the number of P/E cycles is usually an even thousand and it's also inline with the increase that the 850 Pro saw (from 3,000 cycles in the 840 Pro to 6,000 cycles).

Samsung SSD 850 EVO Lifetime Estimation
  120GB 250GB 500GB 1TB
Raw NAND Capacity 128GiB 256GiB 512GiB 1024GiB
NAND P/E Cycles 2,000
Raw NAND Endurance 250TiB 500TiB 1000TiB 2000TiB
Lifespan with 20GiB of Host Writes per Day with 1.5x Write Amplification 23.4 years 46.8 years 93.5 years 187.0 years
Lifespan with 100GiB of Host Writes per Day with 3x Write Amplification 2.3 years 4.7 years 9.4 years 18.7 years

While write endurance in client workloads was never truly an issue even with planar TLC NAND, the doubled endurance in TLC V-NAND makes it practically impossible to wear out the drive before it has become totally obsolete. Only some very extreme workloads could wear out the smaller capacities before the warranty runs out, but the 850 EVO is a wrong drive for such workloads in the first place. All in all, there should be absolutely no reason to worry about the endurance of the 850 EVO, especially given the endurance ratings Samsung is giving to the 850 EVO (75TB for 120/250GB and 150TB for 500GB/1TB).

Three Bits and Three Dimensions: What's the Deal? Performance Consistency & TRIM Validation
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  • sylerner - Thursday, August 13, 2015 - link

    The over-provisioning figures in the article are larger than the actual over-provisioning values.

    The source of error is failure to account for the flash memory used for TurboWrite.

    The correct values are:
    120GB: 10.6%
    250GB, 500GB and 1TB: 8.0%
  • Lonerski - Sunday, January 31, 2016 - link

    Did you use Rapid Mode in those benches ?
  • CricDasher - Thursday, March 3, 2016 - link

    Samsung SSD 850 Evo is a life-changer for anyone who uses it. With the sleek and beautiful build quality, Evo 850 does obviously come with a great price tag.

    There are of course different capacities of the given product, but I preferred to use the 120 GB version, largely due to the relatively low price and my actual need of owning an SSD.

    My major requirement was to install the Operating System and few other mostly used applications inside the SSD, so that the whole computer looks so fast. Samsung Evo 850 120 GB SSD has done the job fantastically for me so far and I highly recommend this product to everyone.

    Out of the sellers online, GearBest seems to offer the best package since GB is a trusted source of products. They are offering a flash sale at the moment and you may try it to get it for a relatively a low price.

    http://www.gearbest.com/hdd-ssd/pp_311494.html?vip...
  • Budburnicus - Friday, March 11, 2016 - link

    Samsung OWNS the SSD market! When I can buy an 850 EVO 500 GB model for just $110 and get for all intents and purposes, the BEST possible speed from a SATA 6 drive - there is REALLY NO POINT in buying ANY other brand!

    I mean the 850 EVO keeps up with, and sometimes even SURPASSES the 850 PRO - often in ways that will benefit the average power user/gamer more!

    I wonder how much of that is due to the 6 GB of SLC write cache - as the 850 PRO series has no SLC NAND whatsoever!

    Also, once the "Magical" storage capacity of 480 GB and above is reached, again, for JUST $110 - not only is that more than sufficient to hold my OS and all the games I play, but all SSDs tend to perform best at 480 GB and above, I would say for the 850 EVO series, this is DOUBLY TRUE! Due to the fact that the 500 GB model has a full 6 GB of SLC Turbo-write NAND (compared to 3 for the 250 and 120) - but it also has a full 512 MB of DDR3L on it!

    I dunno why Anandtech has it listed as DDR2L memory, but it is indeed DDR3L RAM on ALL Samsung 850 series drives!
  • Tornadotuan - Friday, July 8, 2016 - link

    Hi Hardware Community,
    I know this article is quite outdated right now, nevertheless the actual topic of the authors "Final Words" bug me right now. Especially now that enough time for longtime-endurance tests has passed.

    Anyway, I can´t choose between the Samsung EVO 850 1TB v2 (289€) and die SanDisk Extreme 960GB (281€).
    So pricewise the "Pro" is even cheaper right now compared to the Samsung. But there are some obvious differences:

    - TLC 3D V-NAND vs. MLC Planar
    - 5 years vs. 10 years warranty
    - 150 TBW vs. 80 TBW
    - higher Peak vs. consistency
    - Samsung Bugging vs. sudden death drives

    My usage:
    - Client for everything: gaming, programming, office, multimedia - averything
    - gonna split it in system and data-partition
    - gonne be in laptop that´s used as desktop
    - battery is wasted, so no concern about power consumption

    So, usually I use hardware until it´s broken so meaning about 8-10 years.
    Still I want steady performance without sudden decline in speed like with the EVO 840 :C
    I´d be really glad, if you could tell me your opinion on this :)
  • Robbin1111 - Saturday, April 28, 2018 - link

    Awesome drivers! Anyone has a code for this? I checked several sites, like
    https://www.retailmenot.com/coupons/samsung,
    https://dealspure.com/Samsung-Electronics-Promo-Co...

    but couldn't find one. My mom has an aging Dell D830, which is very slow and I'm looking for a reasonably priced replacement, and I think this driver is great.
  • rocky12345 - Thursday, January 30, 2020 - link

    Yes this is a older review but just posting in 2020 on how my Samsung 850 EVO 500Gb has stood up to the wear & tear of every day computing. I have had my drive since 2015 in a computer that is on for many hours a day since I got the drive.

    The system gets used a lot so everything gets a really nice work out everyday. According to the Samsung software my drive is only at 2% of it's rated endurance lifespan. Not to bad for a drive that gets hit pretty hard everyday with reads and writes and to still have 98% life endurance left after all these years of use.

    I read this review back in 2014 and it was one of the reasons I decided to get this drive for my system. I just came from a new write up form this site talking about a Midrive setup. What got me thinking about TLC nand was not the write up itself but a comment from a user and how they were saying just how bad QLC & TLC nand was and how they had low endurance lifespans.

    Am I missing something here? My drive has TLC 3D V-nand made by Samsung and the drive is still at 98% endurance left on the SSD. Is Samsung's 3D V-nand better than regular TLC chips and lasts longer because of it. Yes my drive is getting up there in age and I plan on replacing it once I do a full system update and I will be getting a much faster NVMe PCI-e 4.0 drive.

    As for the Samsung SSD I probably will use it to cache my 4 4TB hard drives since AMD has that caching setup in their platform and I can still find a good use for the Sata SSD I currently have. For now it is very snappy and the system feels very fast still with things such as Chrome or Firefox opening in half a second or Windows still booting up in a mere 7 seconds right after the bios post screen to the desktop so not worried about speed just quite yet.

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