Will iMac SSD degrade over time?

Discussion in 'iMac' started by seasurfer, Aug 12, 2010.

  1. seasurfer macrumors 6502a

    Dec 12, 2007
    I never used an SSD before, but I have been reading a lot about it lately as I am intending to buy an iMac with SSD.

    My questions here is will SSD degrade over time? I heard that writing speed will degrade over time, how true is that? What is your personal experience?

    I like to download a lot, that means I also delete a lot. If I download directly to my SSD, will it shorten its lifespan?

    Also will surfing the internet shorten its lifespan? Since browser caching is constantly saving things on the SSD?

    Kindly share your experience. Thanks.
  2. TheBritishBloke macrumors 68030


    Jul 21, 2009
    United Kingdom
    Nobody could tell you much.. As they haven't been around long enough for anyone to see any problems such as this.
  3. soonlar macrumors newbie


    Sep 1, 2007
    Twin Cities, MN

    Look for an SSD with garbage collection. The new ones use the Sandforce controller and seem to hold up over usage and time tests. OS X doesn't support Trim in its OS yet, so it is critical to get an SSD with garbage collection features. The fine folks over at OWC (macsales.com) have several SSD drives that fit the bill, specifically the OWC Mercury Extreme Pro

    Good luck.
  4. symbology macrumors regular

    Aug 4, 2010
    If you were always downloading compressed files, or files which cannot be compressed like video and media file then you very well could run into issues with any MLC SSD.

    Under normal use you should be fine.

    If I was you, I would download your media to a normal HDD.

    I'm afraid the manufactures are concerned that their SSD's will not hold up over the long haul if heavily abused. Therefore, they use throttling technologies to limit the write capabilities to the SSD. They purposely slow you down.

    On the Sandforce drives and I think most others, they throttle back the writes of non-compressible data. Non compressible data is data such as media files, video, music or any previously compressed file.

    It may take you a while to understand this, but I recommend you read into the following thread.


    Bottom line, if you plan to move a lot of large media files onto and off of an SSD, you can expect slow write performance to crop up regardless of the controller.

    Normal use you should be fine.
  5. wirelessness macrumors 6502

    Jun 20, 2010
    Slow write performance being very relative. Not slow compared to a HDD.

    SSD Degradation is not the same thing as slow write performance of non compressible files. Devices that do not have the built in ability to clean up parts of the drive where unused data is being left behind by write operations then the drive will degrade over time no matter what kind of files you work with maybe not as fast but it will degrade. Drives without garbage collection are fine for Windows 7 systems with Trim support. No so much for OSX sans Trim. Over time and degradation are relative terms.....depending on use it might not be too severe for several years. Or much sooner if you are moving a lot of data around.
  6. symbology macrumors regular

    Aug 4, 2010
    Sorry, but I disagree. I think the term degradation in relation to SSD's is a very loosely defined and very broad term. Anyway, if you really take the time to read through the post that I linked to, and others like it you will see that the write performance of non compressible files is what degrades the soonest on many SSDs.

    You mention Trim, if you read through some of the issues with even the Sandforce controllers you will see that Trim is not effective 100% of the time. It has to do with the fact that consumer based SSD use cheaper MLC NAND that, under what I would consider heavy use, will not last more than a few months without complex protection built in. When I first looked at SSD technologies, and Trim, and GC you think that the issue that the SSD manufactures is dealing with is cleaning up after file deletions and insuring that there is plenty of free / clean space to write to. After doing some further research that is not the case. Their major issue is the longevity of the drive and how to mange the NAND and keep things working for 3 years to satisfy their warranty period.

    Research the term "Write Amplification". They are all after high "Write Amplification". This is something that is not a concern at all on a std HDD.

    With Trim..... Basically, even if you had a Windows system that supports Trim and you write / erase lot of non-compressible data, you wil bypass Trim and enable GC control of the SSD. This is where the Sandforce Duraclass and Durawrite kick in and take over the SSD. Regardless if Trim is enabled or not. One of the reasons why I think that OSX may never have Trim support. The Firmware of the drives have and are going to take control of that functionality.

    Read through the above link I provided where you will see some great information being "pried" away from the OCZ Tech on the forum. Then, read the below FAQ from Sandforce and maybe you too will have a different outlook on SSD drives.


    I am not trying to scare anyone away from SSD's, under normal conditions you will not run into issues and you will be happy. However, if you do a lot of benchmark testing (with certain apps), or write / erase a lot of non compressible files you may be in for a surprise when your SSD writes start to crawl compared to when it was new.

    I am no expert, and all I am trying to do is relay information that I gathered after doing a lot of research on SSD's before making my purchase.
  7. symbology macrumors regular

    Aug 4, 2010
    How do you know? Really?

    I am not sure these test are all that accurate. Sandforce controllers use heavy data compression to keep the Write Amplification very high. With high compression, the disk may be telling you it is writing 100GB, but in reality it could be writing much, much less. With his use of "Disk Tester" generated files, that appear to all be the same minus the file name, well you have major file compression abilities.

    If you would take the time to read through some of the stuff I linked to, you would see how invalid some of the testing apps are against the Sandforce drives. Especially, if you plan on moving a lot of media files in and out of your SSD drive! You could be in for a shock.

    Please take the time to read this before recommending that someone spend $$$ on something that may, or may not work out for them.

  8. Warbitrary macrumors regular

    Nov 24, 2009
    Montréal, Canada
    I do not know, I trust the experience of the guy I linked to, who works with media files and SSDs daily.
  9. symbology macrumors regular

    Aug 4, 2010
    Which is fine.

    Do you not trust someone that works for OCZ when it comes to how the Sandforce controller works? And... which type of test and data provide a specific result?

Share This Page