SSD endurance: Death by petabyte

SSD endurance: Death by petabyte

Summary: In an endurance test six consumer-grade SSDs have been written to continuously until failure. The good news: They all exceeded their endurance specs by a substantial margin. But half have failed before reaching a petabyte of writes.

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The good folks at The Tech Report have subjected SSDs from Corsair, Intel, Samsung, and Kingston to a write-until-failure test to see how long they last and how they fail. If you are professionally interested read the entire piece. But here are the high points.

While all the drives handled over 700TB of writes - far more than they'd see in normal use - three failed before reaching 1PB. A Kingston HyperX 3K died at 728TB, while an Intel 335 reached 750TB.

The Samsung 840 250GB - using three-level cells that have lower endurance than MLC - was the next to fail at over 900TB.

Dance of death  Most drives all warned of imminent failure - giving enough time to back up data - but then had different behaviors. 

The Intel media wearout indicator (MWI), available through the SMART interface, showed the drive was done. At that point the drive is supposed to go into a read-only state, but after more writes and a reboot the drive was detected as a 0GB SATA drive.

There were two HyperX 3K SSDs, one writing incompressible data while the other got compressible data to test the controller's DuraWrite technology. DuraWrite does inline compression and full block writes to reduce wear.

The incompressible HyperX died after several warnings, and then bricked after a reboot. It appeared the HyperX died after using all the available flash.

The Samsung 840, whose TLC flash has roughly a tenth the endurance of MLC, started bad block replacement at only 200TB. At 300TB it began showing uncorrectable errors, causing it to fail some tests. But it still worked at 900TB before dying without any SMART warnings.

The Samsung 840 Pro with MLC has kept working beyond 1PB, but it isn't clear what the failure mode will look like. The Corsair and the other Kingston also carry on.

What does this mean to you?  If you are creating or editing spreadsheets, documents and presentations, you'd have to be pretty busy to update even a gigabyte per day, or a terabyte every 2-3 years.

If you are editing video or music you might write 100GB a day, or a TB every 10 days, and it would take you over 13 years to reach 500TB. Bottom line: all these drives have plenty of endurance for consumer uses.

The Storage Bits take  These are encouraging results. The drives comfortably exceeded their endurance specs, addressing a major concern that many sysadmins have had with SSDs.

The differing failure modes suggest that larger shops will be happier buying one brand whose behavior they can learn, rather than buying on price. While most workloads aren't going to ever write a petabyte, there are other factors - such as multiple die failures - that could cause some drives to fail sooner than expected.

Given that these SSDs are all consumer-grade, their endurance is remarkable. But there are reasons other than media wear out for SSDs to fail, so back them up just as you would a hard drive.

Comments welcome, as always.  Have you had any media wear out on your SSDs?

 

Topics: Storage, Hardware, Intel, Samsung

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32 comments
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  • Article Error?

    "The Samsung 840, whose TLC flash has roughly a tenth the endurance of MLC, started bad block replacement at only 200GB. At 300GB it began showing uncorrectable errors, causing it to fail some tests. But it still worked at 900GB before dying without any SMART warnings."

    Should it be GB or TB? Assuming TB.
    robradina@...
    • Thanks!

      Fixed.

      Robin
      R Harris
  • How does this translate into "years of use".......

    .....on the "average" consumer PC/Tablet?
    kd5auq
    • My thoughts as well.

      That is lots of writes and how does this compare to platters?
      Bruizer
    • How much data is in these numbers.

      1 terabyte = 1 trillion characters or 220 million pages of text, or 440,000 novels at 500 pages per book, or roughly 5 public libraries.

      1 petabyte = 1,000 terabytes or 3 years data from all earth orbiting satellites
      kmajors@...
      • 1 pentabyte

        4K video or multichannel FULL HD can run you around 20gb an hour in real time. IF you are using an SSD to process video faster than real time, then you will go thru more than 20gb an hour of writes. 200gb an hour not uncommon for batch processing.
        That's easily 5tb a day of writes, and hitting the failure zone in 3 or 4 months.
        warboat
      • or 64KB's ..

        ... all the RAM anyone will ever need (a less than flattering prediction by Old Bill, many moons ago) ;P
        thx-1138_
    • Think about your usage

      If you are creating or editing spreadsheets, documents and presentations, you'd have to be pretty busy to update even a gigabyte per day, or a terabyte every 2-3 years.

      If you are editing video or music you might write 100GB a day, or a TB every 10 days, and it would take you over 13 years to reach 500TB. Bottom line: all these drives have plenty of endurance for consumer uses.

      Robin
      R Harris
      • the real problem

        Is that SSD failure does not follow a standard deviation bell curve.
        All you need is one to fail on you to make it hell.
        Sample size here is only 6, and 1 of each.
        Hardly scientific.
        warboat
  • This is actually concerning

    There are many reasons a disk is written to and read from and it isn't just user-initiated activity like saving documents. The operating system and applications generally use disk in the background to varying degrees. So, given all the possible disk activity from the combination of system, application and user, 900 TB is not an extensive amount of disk activity. The results of these tests should raise concerns for everyone that uses SSD's. I am an SSD fan, but if the data is not recoverable after these failures, I am going to have to rethink my disk and storage strategies.
    Cloud Guy
    • That's why you back up your data

      Relying on a single point of failure for your storage of important data is a recipe for disaster with no recovery. A spinning hard drive is going to fail, probably in a comparable amount of time. If you're not backing up your data and your drive fails, any type of drive, and you lose the data there's one reason to blame the loss of data, and that would be you.
      BrewmanNH
    • Not really. Writing non-stop at 100 MB/S

      24/7 would get you to 500 TB in about 19 days. In real world use on a low memory system, you'd be hard pressed to write more than 100 GB a day in and out of swap. So, even if you were in a worst case scenario of running Video editing on a low memory system, it's still a safe bet you aren't doing more than 200 GB a day in writes. That still gives you about 6 years before failure.
      baggins_z
    • I don't see the OS rewriting that much data

      in general. Even if the system had minimal RAM and was hitting the swap file consistently, it isn't going to use up much more than video/music editing.
      grayknight
      • OS's do a lot of back ground

        OS's often set and access time each time a file is opened. That is a write. It is best to tun that off to extend SSD life. But it really might save a couple of months of use. Also Trim must be done properly and it really extend things use a non-journaling files system.
        gogalthorp
    • Well actually if you read up

      on SSD's it's recommended that you don't have a page file or move it to a HD. By doing that alot of the activity goes away.
      Orlbuckeye76
      • Pagefile in RAM

        I have yet to go down the SSD path but in any case I have a portion of RAM allocated as a drive, to which the pagefile is assigned. This speeds up my system, reduces disk writes and in the case of an SSD, would extend the working life to some degree. If your system has enough RAM then turn off the pagefile. I am still working with some old hardware that has an 8GB maximum RAM, so a pagefile is almost unavoidable.
        DOSlover
    • Three sure things in life

      Death, taxes, and all hard drives will fail.
      jvitous
    • The Point Was

      If you go to some of the SSD mfg sites, they explain that this is really not a "failure" per se. The technology for SSDs imposes a limited number of write cycles on a drive. What I heard reported from someone who bought a very old used drive, was that the drive is supposed to become read-only and not lose the data. Of course, if the OS can't write to the disk, maybe access would be "off' anyway. As someone pointed out, that is why we have backups. You all do backup the PC, no??
      hforman@...
  • Endurance is actually pretty good!

    These numbers are showing that if you are being even the most conservative with your backups, SSDs not only provide great speed but enough longevity to outlast most system's usefulness.

    I've installed several SSDs in my own systems for boot up speeds and have 2-3 terabyte hard drives for the larger data sets. But I was a bit worried about Windows 7 background data activities and the wear created by them but looking over the numbers... well these machines will have been 'retired' before I get anywhere close to them.
    Technocrat@...
  • Here's a Metric

    I've been using a 128GB Samsung 840 Pro for over a year with Windows 7 Pro. The SSD is my boot drive (C:\). I relocated all personal folders and Windows Search data to other drives. No hibernation file, pagefile, or prefetch on C:. No defrags. In theory, there should be very little writing to the SSD, right? Wrong!

    In practice, Samsung Magician reports I'm writing the equivalent of about 1.5 TB/year (about 4 GB/day) to the SSD. Still, at that rate, I'll be long gone before my SSD dies.
    SteveMak