1TB Fusion Drive max RAM?

Discussion in 'iMac' started by Bronze84, Nov 28, 2016.

  1. Bronze84 macrumors newbie

    Oct 7, 2012
    Hi guys,

    So I've just bought the mid spec (late 2015) 27" iMac with the 1TB Fusion Drive.

    I'm wanting to increase the RAM. At the minute it has the standard 8gb and I was going to buy an additional 16gb to bump it up to 24gb total RAM. As you all know the SSD bit of the 1TB Fusion Drive has been reduced to only 24gb. My question is, can the 1TB Fusion Drive handle 24gb RAM or will it only be able to handle 16gb total? I know that if I was to upgrade to 32gb RAM then performance would be affected (and Apple advise the 2TB/3TB Fusion Drive for this), but it doesn't actually say anywhere what the maximum RAM is for the 1TB drive.

    Thanks in advance for any help.

    ..... Sorry for the excessive use of 'RAM' ;)
  2. chrfr macrumors 604

    Jul 11, 2009
    There's no relationship between disk configuration and RAM compatibility. Upgrade to whatever amount of RAM you wish.
  3. Bronze84 thread starter macrumors newbie

    Oct 7, 2012
    Thanks for the reply. If I upgrade to 32gb Apple even say there will be performance issues as the 1tb fusion drive cannot write a full disk image to the SSD part of the drive. I don't want to loose any performance
  4. thats all folks macrumors 6502a

    thats all folks

    Dec 20, 2013
    Austin (supposedly in Texas)
    please see:

    either there is something you are leaving out of your question or you are misunderstanding the information you were given.
  5. JustMartin macrumors 6502a

    Feb 28, 2012
    Are you talking about safe sleep? That is, when an image of the Ram is made on disk? With autosave and windows restore, I don't think you need to worry about having that turned on. Regular sleep turns off everything apart from RAM, safe sleep is only needed if you're going to lose power (like battery running down). Not an issue with an iMac.
  6. Samuelsan2001 macrumors 604

    Oct 24, 2013
    It may mean it takes a few more seconds to wake from sleep if you have more than 24gb in your ram when it went to sleep. Other than that it will not matter at all. You will never notice basically.
  7. maflynn Moderator


    Staff Member

    May 3, 2009
    32GB of ram means you'll swap out to disk less, since OS X can work in memory without pushing ram pages to the disk, but as others stated, putting the computer into hibernation will mean a sleep image file greater then that of your flash storage. Even if you it wasn't greater then the flash storage, OS X, may use the spinning HD for something like this.

    Either way, you'll only notice this when waking the computer up

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