Initialize an SSD in OS X® Yosemite and earlier

If you have upgraded to OS X 10.11, go to our new guide for El Capitan and later.

Before you can use your new SSD with your Mac® computer, you have to initialize and partition it.

  1. Connect the SSD to your Mac system (either externally using a SATA-to-USB adapter or internally in the system). After the drive is connected, open Disk Utility (or boot to your OS X Recovery Utilities and access Disk Utility, if the SSD is internal). When the SSD is detected by the Mac computer, you will see a message telling you that the drive cannot be read by this computer. In this message, click the Initialize button.
  2. The Crucial® SSD will now be listed in Disk Utility in the left column. Highlight the SSD and click the Partition tab.
  3. Click on Options and verify that it's set to GUID Partition Table.
  4. Select Partition 1 if you want to use the entire SSD as a single partition and give it a suitable name.
  5. Verify that the selected format has defaulted to Mac OS Extended (Journaled).
  6. Select Partition. The drive will now be partitioned and formatted.
  7. When the Disk Utility is done, close it.

The SSD should now be visible on your desktop with the new name you gave it. If you have not yet installed the SSD internally and wish to do so, more information is available here.

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