SSD - LBAs Written increases to quick

Discussion in 'MacBook Pro' started by MacUse-R, Mar 7, 2018.

  1. MacUse-R macrumors regular

    MacUse-R

    Joined:
    Dec 24, 2017
    #1
    I just bought a new Samsung 850 EVO 500GB SSD disk and installed it in my MacBook Pro Late 2011 a couple of days ago.

    I check the SSD with the DriveDX software and I noticed that the written data to the SSD (LBA) increases very quickly without me doing basically anything at all that would be writing data to the SSD?

    For example in only the last day (of which I only have been using the MacBook Pro for a couple of hours for browsing) it says it has written 32GB to the SSD.
    The rest of the day the MacBook Pro has been in sleep mode.

    What is going on here? What can cause the MacBook Pro to write this much data to the SSD without me doing basically anything that should cause it to write this much, at least this much?

    Some help would be appreciated.
     
  2. DeltaMac macrumors G3

    DeltaMac

    Joined:
    Jul 30, 2003
    Location:
    Delaware
    #2
    Between reads, and writes of various cache files, and other temp files that are created, and used, on the fly, your Mac boot drive is almost always active in some way. Only two days of use, can mean that much of the cache stucture, and the various database files that the system maintains is probably still being optimized.
    That's most of the reason why your system may take a couple of days use before the true speed of the system is realized.
    32GB of writes in a day is probably not a stretch (and pretty normal) with a fresh install in a typical macOS system, and is one of the issues that makes an SSD a really good test of your system (and lots of the reason that hard drives can be so slow, particularly in the last couple of macOS systems.
    You will also likely notice that a lot of that 32GB of writes is probably not taking 32GB more space, but a lot will be writing changes to files that are already in place.
     
  3. MacUse-R thread starter macrumors regular

    MacUse-R

    Joined:
    Dec 24, 2017
    #3
    Thanks, yes you are correct that the written data is not reflecting the available Gigabytes on the SSD. I still have 478 GB from the 499 GB on the SSD even though the total number of GB written to the SSD is way more than the 21 GB used on the SSD.
    Yeah I hope it lowers the amount of data it is writing to the SSD after some time of using the SSD? I was a bit concerned on the wear level of the SSD if it is writing too much data all the time.
     
  4. DeltaMac macrumors G3

    DeltaMac

    Joined:
    Jul 30, 2003
    Location:
    Delaware
    #4
    I think you would need to exceed a few TB/day before you could be concerned.
    From what I read, modern SSDs for personal use really don't get used at a level that will get close to wear limits.
    Even at 32GB/day - the practical life might be 15 years or so.
    One of the reports that I just read mentions that the wear limit expectation, using the data point of completely overwriting the complete drive 3 times/day - that SSD should be expected to last around 85 years.
    My point is that lifetime wear needs to be considered, but it's not really practical information for the normal user, and in real-life doesn't determine how long the SSD will last for you (your other hardware may be long gone before the SSD (finally) wears out :cool: )
     
  5. MacUse-R thread starter macrumors regular

    MacUse-R

    Joined:
    Dec 24, 2017
    #5
    That sounds reassuring. Yes I guess there is a pretty good chance the MacBook Pro will stop working before the SSD considering that its a Late 2011 MacBook Pro.
     

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4 March 7, 2018