How reliable are SSD's?

Discussion in 'Mac Pro' started by tony3d, Jun 15, 2012.

  1. tony3d macrumors 6502

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    Apr 6, 2006
    #1
    I have been reading people are having trouble with Ssd failures. You would think they would last a long time. Does anyone buy Apples Ssd?
     
  2. maflynn Moderator

    maflynn

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    #2
    I've only seen a handful, my SSDs are going strong, one almost a year old, the other 2 years old
     
  3. MJL macrumors 6502a

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    Jun 25, 2011
    #3
    I am not worried about it. However SSD have a limited number of times that they can write to the SSD so I would not want to rewrite the whole SSD every day. I installed recently my fourth SSD and all have been going fine. I write a few Gb each day.

    A study by Toshiba done some years ago showed the average user writing less than a Gb a day and the power users up to about 5 Gb per day. Their ssd's are configured for a 5 year lifespan writing 20 Gb per day for a 128 Gb SSD. That's 5 DVD's.

    With photo and movie editing then you might well go to the upper limits of writing and I would not advise a SSD. Just have the OS on the SSD and the data on a HDD. There is some website that keeps statistics of the most reliable hardware (forgot which one) and at the time the Intel, Toshiba and Samsungs were leading the pack. I believe these days Crucial is pretty decent too.
     
  4. tony3d thread starter macrumors 6502

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    #4
    I didn't realize there was a limit to how many times you write to it. Why is that?
     
  5. MJL macrumors 6502a

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    Jun 25, 2011
    #5
    Nature of the semiconductors, the memory cells "wear out".
     
  6. DanielCoffey macrumors 65816

    DanielCoffey

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    #6
    I have had an OCZ Vertex2 120Gb 3.5" for about two years or so now without any issues as my OSX boot drive and another OCZ Vertex2 240Gb 3.5" for a year as my Windows7 and steam games drive. Neither has given any hiccups and both are running the latest firmware from the supplier.

    All reputable SSD manufacturers offer a good warranty which is comparable with HDDs anyway.

    I do have HDD Time Machine backups of course but you should have some sort of backup regardless of whether you have SSD or not.
     
  7. atlanticza macrumors 6502a

    atlanticza

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  8. Litany macrumors member

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    Jun 5, 2012
    #8
    They are much more reliable than hard drives.

    I have had 6 hard drives (out of about 30) fail over 20 years. All 4 SSDs I have bought over the last 4 years are still working like new.
     
  9. ProBill, Jun 15, 2012
    Last edited: Jun 15, 2012

    ProBill macrumors newbie

    ProBill

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    #9
    Looking at some info on the web (2008 material), the endurance of the kind of NAND flash memory used by Crucial ("MLC", i.e., multiple bits/cell), a user would have to write about 22 Gbytes of data every day for 5 years to wear out the device (assuming a 128 GByte device). The controller manages the wear-out by moving the writes around the device and also has a "bad memory block" management (BMM) to mitigate failures. Further, EDAC is employed to minimize the impacts of small errors. Other more endurable memory ("SLC", single bit/cell) has a capability for an order of more program-erase cycles and is faster - and is more expensive. Bottom line is that SSDs should be very reliable under normal circumstances. That being said, who is a 22 GByte/day+ user? I suppose if you are doing some heavy duty video processing, you might begin to see early wear-out. I would expect that the BMM to mask some failures with the user only observing reduced storage capacity. It would be interesting to know from some SSD owners if their SSDs provide health and statistics of the devices. One caution is that the above, again, is based upon 2008 information. The manufacturers are constantly doing two things: 1) improving the inherent reliability of their devices and 2) increasing the performance via increased density of their devices, thereby potentially decreasing the endurance of the device. To the first order, those two effects may be simply cancelling each other out leaving the overall performance at 10K program-erase cycles/cell for MLC and 100K for SLC. (But ignore this, are you a 22 Gbyte/day for five years kind of user?)
     
  10. Spacedust macrumors 6502a

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    May 24, 2009
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    Poland
    #10
    My SSD's tests:

    1x Intel X-25 M 80 GB - almost 8000 power on hours, 11 reallocated sectors working ok
    2x OCZ Vertex 3 120 GB - one is more than 4000 power on hours old, the other is about 2000, no problems at all
    4x Kingston SS100S2 16 GB - all went for RMA, bad clusters, missing files, corrupted file system etc.
    1x Kingston SSNow 40 GB - 2 reallocated sectors, working ok
    5x A-data S396 30 GB - 4 of these working fine in RAID 0 now, one failed completely after just one month
    1x A-data S599 40 GB - 434 hours, no problems so far, can't update firmware on a Mac, even on BootCamp (need Intel chipset board with native AHCI bootup).
     
  11. philipma1957 macrumors 603

    philipma1957

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    Howell, New Jersey
    #11
    I have had good luck with most ssds. I have owned used tested sold more then 200 ssd's of different types.

    Of this years models;

    crucial m4 128gb 256gb 512gb are very reliable .

    Samsung series 830 128gb 256gb 512gb are very reliable.

    The 64gb of both are slower but do not break.

    Intel has been very good to me 330's 520's g2's.

    Last years samsungs series 470-810 were really good.

    For break down lemons ocz patriot and corsair. all failed on me (fast under 60 days).

    to be fair these were older models purchased in 2010 failed in 2010 and I never purchased any new ones to test.

    right now I would say a 256gb samsung 830

    a 180gb intel 330

    or a 256gb crucial m4 all good for not breaking
     
  12. Loa macrumors 65816

    Loa

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  13. deconstruct60 macrumors 604

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    Mar 10, 2009
    #13
    It isn't a myth.... from the article quoted

    " ... even the worst 25nm compute NAND will last you well throughout your drive's warranty. ... "

    They do wear out. Folks who look and "Solid State" and think "oh I can abuse use this for 6-8 years" are off base. They aren't going to blow up in a year ( if a well designed one without faulty parts), but they do wear out. Just plan for it wearing out just like disks wear out. It "flash" really isn't solid state as sending the material through multiple significant state changes to "erase".

    Likewise if you are going to abuse the drive things are different. Like write write 70GB or 170GB per day to the drive instead of the article's 7GB; again more abuse the faster they wear.

    Wear leveling isn't going to be perfectly implemented. To deal with data at "wire" speeds most of the heuristics used are not omniscient. These back of the envelope projections are just that 'back of the envelope". They are good for stopping Luddite arguments about how SSDs are too fragile for critical data, but don't really dispel that wear is a criteria to be considered if dealing with high I/O write contexts.
     
  14. Loa macrumors 65816

    Loa

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    Québec
    #14
    Hello,

    Well, even a diamond rubbing will wear out, if you want to present it that way...

    Here are some other quotes: "Paired with a decent SSD controller, write lifespan is a non-issue."

    A non-issue.

    Also: "The worst write amplification we saw was around 0.6x. [...] In this particular drive the user wrote 1900GB to the drive (roughly 7.7GB per day over 8 months) [...]. This includes garbage collection and all of the internal management stuff the controller does. Over this period of time I used only 10 cycles of flash (it was a 120GB drive) out of a minimum of 3000 available p/e cycles. In eight months I only used 1/300th of the lifespan of the drive."

    That makes write-wear a non issue for nearly all users.

    Loa
     

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