Is SSD performance impacted by available space?

Discussion in 'MacBook Pro' started by ghanwani, Jul 26, 2019.


What % of your SSD space is used?

  1. <= 25%

    5 vote(s)
  2. > 25%, <= 50%

    5 vote(s)
  3. > 50%, <= 75%

    9 vote(s)
  4. > 75%

    4 vote(s)
  1. ghanwani, Jul 26, 2019
    Last edited: Jul 28, 2019

    ghanwani macrumors 65816

    Dec 8, 2008
    I want to see how full people keep their SSD. I currently use about 100 or 500 GB and my use is not going up much.
  2. MacDawg macrumors Core


    Mar 20, 2004
    "Between the Hedges"
    My 1TB internal SSD on my 2013 MBP is about half full
    I have had it very full, and I felt that my performance suffered for it
  3. Howard2k macrumors 68020


    Mar 10, 2016
    I have a 256GB. When I get down to 50GB free I clear up space to push back to between 100GB-150GB free.
  4. velocityg4 macrumors 601


    Dec 19, 2004
    A little over half full. I keep most of my data on my server.
  5. Broadus macrumors 6502a

    Oct 26, 2011
    Upstate SC
    I've read that you want to have no less than 30% free. That's the rule of thumb I go by.
  6. ghanwani thread starter macrumors 65816

    Dec 8, 2008
    I did some searching and found this:
    "As a result of its benchmarks, Anandtech recommends that you “plan on using only about 75% of its capacity if you want a good balance between performance consistency and capacity.” In other words, set aside 25% of your drive and don’t write to it. Only use up to 75% of your drive’s free space and you should maintain ideal performance. You’ll see write performance start to slow down as you go above that mark."​
  7. Michael CM1 macrumors 603

    Feb 4, 2008
    I had a 128GB MacBook Air before I got a 256GB MBP. Oh lord that got awful because of using Windows, Parallels and some other stuff. I have handed that one down to my mom/her grandkids and cleaned off enough to keep 25GB free. I really just needed maybe 150GB of storage. But just like with iPads and iPhones, I don't get a 128GB iPad because I need 128GB. I get it because I need at least 33GB.

    And yes, free space affects performance, especially if your RAM is almost fully used. The OS uses storage as backup RAM. That's one of the many reasons flash storage makes a machine so much faster.

    If I may, semantics: none of these Macs have "hard drives." The generic term is "storage." I know what you mean and I'm not poking fun at you because I still use that term a bunch. But I try to say "storage" to be correct as much as I can. That's 13 years of being a copy editor for you. :)
  8. ghanwani thread starter macrumors 65816

    Dec 8, 2008
    Thanks. I edited the original post to change it to SSD.
  9. Michael CM1 macrumors 603

    Feb 4, 2008
    It's really no big deal. I just have to unleash that old copy editing energy somewhere. :)
  10. ghanwani thread starter macrumors 65816

    Dec 8, 2008
    It’s actually called hard drive on many manufacturer websites! In the grand scheme of things nothing is a big deal, but I’m known to be a bit pedantic myself.

    These terms can be a bit difficult with advances in technology. I would regard SRAM, DRAM, NVRAM, ROM, SSD, HDD, all as storage.

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9 July 26, 2019