Initialize an SSD in OS X El Capitan and later

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Before you can use your new SSD with your Mac, or install OS X onto it, you have to initialize and partition it first. Follow the steps in this article if you are using OS X El Capitan or later. If you have not upgraded, follow our guide for earlier versions of OS X.


1. If you are adding a drive to an existing setup, connect the SSD via USB adapter or other external connection method and enter Disk Utility, or install the SSD internally into your system and enter Disk Utility via the OS X Recovery tool or your installation media. When the SSD is noticed by the Mac, you will see a message telling you that the drive cannot be read by this computer. In this message, click the button Initialize.


2. The Crucial SSD will be listed in Disk Utility. Highlight the SSD and click the Erase button.


  • In High Sierra, we have had reports of the new SSD not appearing for initialization and erasing/partitioning. Two factors are contributing to this.
  • First, the new default for Disk Utility “Show Only Volumes” (a formatted partition of a drive) as seen below keeps the SSD from being seen. Toggling this to “Show All Devices” using the dropdown in the upper-left of the utility is needed.

 Screen Shot 2017-10-12 at 10.10.46 AM.png

  • After this has been done, the displayed list of disks does not automatically refresh. The easiest way to force this to happen is to close and reopen Disk Utility from your Utilities.


3. Type in the name you would like for the new partition and verify that it's set to "GUID Partition Table".


4. Verify that the selected format has defaulted to "Mac OS Extended (Journaled)".


5. Select Erase. The drive will now be partitioned and formatted.


6. When the Disk Utility is done, close it.


The SSD should now be visible on your desktop with the new name you gave it, as well as during the drive selection menu if your run an OSx installer.


If you need assistance with the physical installation of your SSD, we offer guides for installing a replacement SSD here.

Bit Baby
My ssd doesnt even get recognized on both my 2 macbook pros and a pc computer. What now?
Bit Baby

When i click " initialise " in disk utility the box dissapears and the disk doesnt initialise. 


Bit Baby

Just replaced my dead hdd with a new ssd and my MBP didnt recognized it, I bought a new hd cable and still wont appear.

Crucial Employee
Crucial Employee

Ecco come inizializzare un SSD in windows:
1-aprite "start" e nella riga bianca di ricerca scrivete "gestione disco" e premete avanti.

2- Cliccate "crea e formatta le partizioni" del disco SSD.

3- Se il disco è fino a 2TB scegliete MBR ovvero il Master Boot Record.

4- Posizionate la freccia sul disco nero e premete tasto destro e scegliete "nuovo volume semplice". Premete avanti.

5- Specificate la dimensione della partizione che desiderate. Io odio partizionare quindi lascio la massima capacità possibile. Premete avanti.

6-Potete dare una lettera specifica al drive se ne avete un motivo particolare altrimenti lasciate la sua e premete avanti.

7- Il file system (lasciate NTFS nei sistemi windows 7 e 8)
8- Premere avanti fino a completare la formattazione.