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How do I zero out my disk?

Discussion in 'OS X Mountain Lion (10.8)' started by TSX, Jan 15, 2013.

  1. TSX
    macrumors 68030


    I want to zero out my HD and I'm in mountain lion. How do I go about doing this?
  2. macrumors 603


  3. TSX
    macrumors 68030


  4. macrumors 603


    Yep, Erase, Security Options.

    It'll take awhile...
  5. macrumors 68020


    This is going to take a long time, be ready to twiddle your thumbs.
  6. TSX
    macrumors 68030


    I'm in no rush but thanks for the replys.
  7. Moderator


    Staff Member

  8. TSX
    macrumors 68030


    1 pass,3 pass or 7 pass? And how long will it take for a 1 TB drive.
  9. macrumors 6502a


    It depends on which type of security you want to implement. If you really want to make sure the data is never recovered ever use the 7 pass option.
  10. macrumors 68030

    Krazy Bill

    Long enough to grow weary and cancel the erasure about 1/3rd through.
  11. macrumors 6502a

  12. Quad5Ny, Jan 21, 2013
    Last edited: Jan 21, 2013

    macrumors 6502a


    A Zero pass on a 120GB drive takes about a hour at USB2 speeds (33MB/s). A good 1TB HDD today can hit about 130MB/s. So best case is about 2 hours, worst case 8 1/2.

    While it might have been true sometime in the 70's/80's, it's in no way true today. The density of today's hard disks prevent any recovery after the drive has been Zeroed.

    For a HDD all you need to do is a single Zero pass, anything more and your wasting your time. SSD's on the other hand need to have the Secure Erase ATA command sent to them (and this only works if the SSD manufacturer implemented it correctly).
  13. macrumors 6502a


    Didn't know about that. Thanks for the heads up :)
  14. macrumors 6502a

    There's a lot of mis-information spread about the internet on erasing hard drives and recovery of the data. If you have the time, do a Google search for "zeroed hard drive recovery". :p
  15. macrumors 6502a


    Will do! I was talking mostly based on what OSX itself says (or said?) when describing the different security options available.

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