TLC or MLC type SSDs?

Discussion in 'Buying Tips and Advice' started by macstatic, Dec 7, 2013.

  1. macstatic macrumors 65816


    Oct 21, 2005
    I hear that MLC type SSD drives last a lot longer than SLC or TLC drives, but in real life, how much difference are we talking? I'll be replacing an iMac's hard drive with an SSD which is used mostly for web/mail (we keep seeing the OSX beachball a lot when websurfing).

    For low-cost quality-branded drives I've been looking at the Samsung 840 EVO (250 GB) TLC-based drive and the MLC-based Sandisk Ultra Plus (256 GB). The former shows high performance in tests while the latter shows relatively poor performance but is MLC-based and should last longer.
    Samsung's 840 Pro is MLC and performs well but is more expensive, but would the price difference be worth it in the long run (it'll last longer), or do these things mostly only matter if you're using it as a server or something else which does a lot of reads/writes?
    I suppose there will be a lot of read/write cycles with a web-cache as well...
  2. mvmanolov macrumors 6502a

    Aug 27, 2013
    web-cache will I've you some but not nearly enough to wear the drive out faster than projected. i;d go with the EVO you are not using it for moving and modifying large files which will put wear on the drive so it is more than likely that you'll end up upgrading the machine long before the drive starts failing :D
  3. Weaselboy Moderator


    Staff Member

    Jan 23, 2005
    That right there is your answer. Unless you are really hammering the drive all day with REALLY heavy write activity, the drive will last longer than your computer.

    Look at the table below from this article. Also read this article.

  4. jnpy!$4g3cwk macrumors 65816


    Feb 11, 2010
    SLC lasts much longer than MLC, and MLC longer than TLC. SLC drives are very expensive and mainly used for storing constantly-written performance-critical files like certain commercial database index files.

    MLC drives are a bit lacking for use in server settings, but SLC drives are so expensive. What to do? Recently, "enterprise" MLC, labeled eMLC has come out that should provide 10,000-15,000 p/e cycles. This should work fine for most general applications and is still cheap enough to be used for operating system drives.

    Which type is best depends on your application. For your application, my guess is that your money is probably best spent buying a larger-capacity MLC/TLC drive than a smaller eMLC drive. An SLC drive would be a waste of money -- are you really going to keep those systems for 20-30 years?

  5. macstatic, Dec 8, 2013
    Last edited: Dec 8, 2013

    macstatic thread starter macrumors 65816


    Oct 21, 2005
    Very interesting reading!
    It looks like I should check how much data is written to the hard drive on average per day.
    Is this information logged in OSX 10.6.8. and if so; how do I access it?
  6. COrocket macrumors 6502

    Dec 9, 2012
    Go to the disk section in the Activity Monitor application, and it should show you the read in/out to the disk. I believe that it is cumulative since the last time you restarted your computer, so you could restart and just remember to check a day later. Unless you use your computer for something unusual the graph that Weaselboy posted is probably pretty accurate.
  7. LeandrodaFL macrumors 6502a


    Apr 6, 2011
    It makes no diference, and the higher the GB, even longer. Get a 500GB and your kids will use it
  8. alphaod macrumors Core


    Feb 9, 2008
    Also SLC last longer than everything else, but they're very expensive.
  9. macstatic thread starter macrumors 65816


    Oct 21, 2005
    I'm keeping a track of it now.
    Interestingly I also checked my Mac Pro which after 6 or 7 hours has had over 36 GB written! Then I realized it does an hourly Time Machine backup and a full clone each morning to another drive. Working with lots of image files surely won't help either. Fortunately those aren't all SSDs though :)

    During the same timespan the iMac has only written 1 GB! It's got an external Time Machine drive, so I suppose those backups aren't included in Activity Monitor's analysis?

    Is there a way to check how much data is written to a specific drive during a given period of time instead of all disk activity?

    Having done this quick check for the iMac and reading the articles linked to earlier it seems a TLC drive might not be such a bad idea after all. Samsung seems to be getting a lot of praises from users, so the 840 EVO (250 GB) might be the one to go for.

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