Let the drive erase and turn into an encrypted format, this process can take a while depending on the drive type, size, and speed.Choose “Erase” and set a password for the encrypted partition, for now choose a simple password that’s easy to remember, then choose “Erase”.Under “Format” choose “Mac OS Extended (Journaled, Encrypted) – the “Encrypted” part is crucial.Select the hard drives primary partition (usually called Macintosh HD) from the left, then choose the “Erase” tab.At the OS X Utilities menu, choose “Disk Utility”.Reboot the MacBook and hold down the OPTION key, then select the Recovery partition.Always back up important data before formatting a drive, or else it will be gone forever. Though it may be obvious, it’s important to point out and to remember that this process removes all data from the drive, which then becomes unrecoverable due to the highly secure formatting options. Secure Format an SSD (or the OS X Boot Disk) via Recovery Mode Be sure you understand that and are comfortable with that potential before proceeding. For users with an SSD drive, it’s important to note that using the secure formatting options like 7 pass and 35 pass could potentially lead to a reduction in drive life span, or performance degradation, though TRIM is thought to mitigate that risk. The first time will not be the secure erase, it’s the second time formatting that will allow you to achieve the desired outcome. This is very much a workaround, as you’ll technically be erasing the drive twice in the process. The most obvious solution to this problem is to boot the Mac from an external boot drive ( here’s how to make one for Mountain Lion), but that isn’t always an option for everyone, but fortunately there is a workaround that lets you perform a secure erase directly from the Recovery partition itself.

Nonetheless, many users want the option for secure removal of data from the SSD.

The precise reason for this isn’t entirely clear, though some speculate it’s because writing 1’s and 0’s to an SSD can lead to performance degradation and a reduction in the drives lifespan, and that it persists even in the most recent versions of OS X suggests it’s not just a bug.

The newest Macs ship with a Recovery partition rather than a separate external reinstall disk, and if you’ve ever rebooted a newer Mac, iMac, MacBook Air, or MacBook Pro with an SSD from the Recovery partition to reformat the drive, you may have noticed that by default the “Security Options” button is greyed out in the Disk Utility options, seemingly preventing a standard “secure” erase procedure.

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