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Best method for using 2 HD?

Discussion in 'OS X Mountain Lion (10.8)' started by OmarKanawati, Jun 13, 2013.

  1. macrumors newbie

    Hello everyone..

    I installed 2 hard drives on my MBP using data doubler(120 GB SSD in the main tray and 750 GB HDD in the data doubler).

    I need help to decide what's the best way to install the OS (mountain lion) and all my apps on the currently empty SSD, and at the same time, I want to keep all my files on the 750 GB HDD (Which currently have the OS as well).

    Can anyone please tell me what is the best option to do that ?
  2. macrumors 68020

    Why not make a Fusion drive, and let the OS place the files in the best place?
    A Fusion drive can have files in the same folder on different devices, which is much more detailed level of management than "files on HDD; OS on SDD".

    Then you have the appearance of one big drive, and don't have to worry about where you need to put things. And you get the speed of an SSD with the storage of an HDD.
  3. macrumors newbie

    Sounds like a great idea. I will do that :)
    Thanks for your reply.
  4. macrumors 6502a

    Just be aware, in case you weren't, that if one drive in the Fusion setup fails then you will have corrupt files on the good drive. Fusion Drive moves blocks, not entire files, between SSD and HDD devices so if you have part of a large file on the SSD and the rest on the HDD and the SSD fails then the remaining bits of the file on the HDD will be corrupt as well.

    This shouldn't cause more of a problem than two single drives as long as you do what everyone should be doing, and that is have current backups. :)
  5. macrumors newbie

    Thanks a lot, but I am already aware of that ;)

    I was just wondering, is fusion drive the best option for me (performance-wise)?
  6. OmarKanawati, Jun 13, 2013
    Last edited: Jun 13, 2013

    macrumors newbie

  7. macrumors 68020

    Too Long; Didn't WATCH. :D

    Fusion is more efficient than any method of simply "dividing" everything yourself.
    As I've said, it can store files (and indeed sub-file blocks of data) in the same folder on different devices. Anything you don't use often will get moved to the HDD. Anything you use frequently will get put on the SSD. (This is once you've got enough to start using both. Initially, it will fill up the SSD.)
    This could include foreign language segments of apps, instruments in GarageBand that you don't use; it could also put email and user caches on the SSD.
  8. macrumors newbie

  9. macrumors 68020

    What is says is that if you use files that larger than 4Gb in size, you may see some performance penalty when dealing with those files.

    But if you were using those files on the un-fused HDD anyway, then you would get the HDD low performance anyway.
  10. macrumors newbie

    Now, I actually understand :)

    But is there a way to make the space in the SSD more than 4 Gb ?
  11. macrumors 68020

    There's almost certainly a setting somewhere -- otherwise that's not a very forward-thinking model. But I don't know it.

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