What Happens When Your SSD Fails?

When your hard drive dies we all know what happens. You go to turn on your machine one day and your OS doesn't boot, or your drive stops getting detected. But with SSDs their lifespan is far more predictable, so what does happen as they near the end of their life? A well designed SSD will have a good enough wear leveling algorithm to make sure that all blocks in the device get equal usage, so that when they fail, they do so at the same time.

Intel's SSDs are designed so that when they fail, they attempt to fail on the next erase - so you don't lose data. If the drive can't fail on the next erase, it'll fail on the next program - again, so you don't lose existing data. You'll try and save a file and you'll get an error from the OS saying that the write couldn't be completed.

The beauty here is that the SSD knows exactly when it can't erase/program a block, and if the drive knows, then you can use software to ask the drive what it knows. In the near future Intel will be releasing its own SSD tool that will let you query two SMART attributes on the drive: one telling you how close you are to the rated cycling limit, and one telling you when you've run out of reallocating blocks. The latter is the most important because Intel fully expects these drives to outlast their rated limits. As bad blocks develop, the SSD will mark them as such and write to new ones - by telling you when it has run out of bad blocks (or nearly run out of bad blocks), you'll know exactly when you need a new hard drive.

This is hugely important. While Intel's SSDs aren't exactly cheap, the beauty of flash is that it follows the same Moore's Law that CPUs do. In the next ~18 months you'll be able to get a 160GB drive for the price of the 80GB, in another couple of years we'll be at 320GB for the same price (most likely lower as SSD demands increase). Within the next five years we'll be in a situation where the fans in your system are more likely to fail than your hard drive, and if your drive does happen to fail it'll tell you well in advance. How nice of it.

How Long Will Intel's SSDs Last? The Generic SSD
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  • Alleniv - Wednesday, August 19, 2009 - link

    Hi all,
    I report this new review about X25-M, that takes in consideration a comparative with other SSDs and also with HDDs, with several benchmarks ? http://www.informaticaeasy.net/le-mi...m-da-80gb.h...">http://www.informaticaeasy.net/le-mi...m-da-80gb.h...
    Reply
  • Bytales - Saturday, January 03, 2009 - link

    You said this: For example, let's say you download a 2MB file to your band new, never been used SSD, which gets saved to blocks 10, 11, 12 and 13. You realize you downloaded the wrong file and delete it, then go off to download the right file. Rather than write the new file to blocks 10, 11, 12 and 13, the flash controller will write to blocks 14, 15, 16 and 17. In fact, those four blocks won't get used again until every other block on the drive has been written to once

    By this i understand that a bigger capacity SSD, for instance 320 vs 160 will have more blocks and hence you will need more writes to deplete the number a write cycles the SSD was designed for. So for SSD bigger means even longer lasting. IS this TRUE ?
    Reply
  • lpaster - Wednesday, November 26, 2008 - link

    Can you overclock this SSD? Reply
  • Sendou - Wednesday, February 09, 2011 - link

    There are optimization methods available for SSD's which can mitigate performance loss through genuine usage over time.

    One such is Diskeeper's HyperFast Technology.

    There is a white paper regarding HyperFast available at:

    http://downloads.diskeeper.com/pdf/Optimizing-Soli...
    Reply
  • BludBaut - Thursday, March 31, 2011 - link

    I read the pdf article you linked from Diskeeper.

    Based on the information Anand has given in his articles about Intel's technology, Diskeeper's "whitepaper" sounds like crap advertising by a company who's afraid their technology might be considered not only useless but detrimental to use with SSDs. I'm inclined to agree since Diskeeper's own results show a 4x write loss by just *one* "optimization" while Anand's article clearly suggests that the proper design (which he says Intel has accomplished) eliminates the need for Diskeeper's service.

    Until I find more thorough examination of the facts, Diskeeper's remarks make me distrust them.

    On the other hand, Anand's article definitely sounds not just like a puff piece for Intel, but qualifies in my mind as advertising. Wonder how much money Intel has spent on Anandtech? That's not to suggest that anything is misrepresentative (well, it wasn't meant to sound that way, but keep reading and you'll find the one-sided praise will later be partially retracted and I don't know the end of the story yet), but we all know that advertising always leaves out the negatives.

    (Reviews shouldn't sound like advertisements but anyone who's been reading magazine reviews for 30 years knows that's frequently the case. The reviewer's bills get paid by the manufacturers' of the products he's reviewing. But, the reviewer is objective of course. It's a matter of journalistic integrity. Yeah, I believe that. Don't you?)

    One such negative was the promotion of the life of the drive. "20GB a day for five years"? Anand praises Intel for multiplying that by five to "100GB a day for five years" but then tells us that they'll only guarantee the drive for three years and has the audacity to suggest we'll likely have a recourse "if we can prove" ... -- how is anyone going to prove how many GBs a day they put on their computer? The annoyance of trying to keep track is not something 99% of people would do.

    Did you do the math to see how long it takes to write 100GB to a drive with a write speed of 200MB/s? Eight minutes and twenty seconds is all it takes.

    Well, that's great if all you use your computer for is reading articles, checking the news and sales prices and sending email. The drive should last as long as your computer. But if you love video (who loves video???), it's a different story entirely.

    There's another negative that, though first denied, eventually was acknowledged. More than six months later, Anand reports back and says essentially, 'Intel is still the best but the performance does degrade with time and I don't know why.' If he's explained it since then, I've yet to read it.

    So, for those just reading the article, don't get so encouraged that you start drooling. The article has a tendency to make one think, "What am I waiting for? I want one of these puppies!" Unfortunately, Intel's technology isn't as rosy and bulletproof and Anand made it sound.
    Reply
  • kevonly - Friday, November 21, 2008 - link

    I hope you do some benchmark on Samsung's new 256GB SSD. Hopefully it's as good as Intel's. Reply
  • kevonly - Friday, November 21, 2008 - link

    its read/write speed is 200/160 mb/s. Will it sustain that speed in a multi applications running environment?? Reply
  • kevonly - Friday, November 21, 2008 - link

    sorry

    read/write speed is 220/200 mb/s.
    Reply
  • scotopicvision - Monday, November 10, 2008 - link

    The article was an amazing read, fantastic, and well done thank you. Reply
  • D111 - Saturday, October 25, 2008 - link


    Legacy OS like Windows Vista, XP, and Applications like Microsoft Office 2003, 2007, etc. have built in, inherent flaws with regard to SSDs.

    Specifically, optimizations of these OS for mechanical hard drives like superfetch, prefetch, etc. tend to slow down, rather than help performance and is unnecessary to speed up reads in an SSD, but slow it down with unnecessary writes of small files, which SSDs are slower than a regular hard drive.

    Things like automatic drive defragmentation with Vista does nothing for SSDs except to slow them down.

    Properly optimized, even low cost 2007 generation SSDs test out as equivalent to a 7200 rpm consumer grade drive, and typical SSDs made in 2008 or later tend to outperform mechanical hard drives.

    The tests done here have done nothing to "tweak" the OS to remove design hindrances to SSD performance, and thus, have no validity or technical merit.

    The test, as presented, would be similar to installing a 19th century steam engine on a sailing ship, and observing that it is rather slow ---- without mentioning the drag and performance hits caused by the unused sail rigging, masts, etc.

    See the discussion here for a detailed discussion of SSD performance tweaks and what it takes to make them perform well with legacy OS and Applications.

    http://www.ocztechnologyforum.com/forum/forumdispl...">http://www.ocztechnologyforum.com/forum...display....

    Reply

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