I'm considering upgrading the SSD in my mid 2014 MacBook Pro. I'm wondering:

  1. If I backup my hard drive with Time Machine, will I be able to use Time Machine to paste my current content (whole or parts, OS, documents, configuration etc.) to the new (and bigger) SSD?

  2. Would it be relevant (performance wise) to do a fresh install of macOS instead of pasting my old HD content (OS included)?

  3. Any other things I should consider during this upgrade?


3 Answers 3


It would be advisable to perform a Time Machine backup of your current drive, preform a fresh install of macOS on the new SSD and then use the Migration Assistance to restore from Time Machine backup.

Apple support document, How to move your content to a new Mac is a relevant read here.

Performing a fresh install of macOS will give you the advantage of getting rid of the baggage left behind by uninstalled software and best performance as far as OS installation is concerned.

Using the Migration Assistance, you'll be able to restore your user data, apps and configuration.

Make sure to test the Time Machine backup and ensure its sanity before erasing your old drive. Better, verify that everything is OK in the new drive after migration.

A non-functional backup is as good as no backup.

Additional Note: As mentioned by Tetsujin, run Migration Assistant at the first run of the newly installed OS, otherwise you end up with 2 accounts & have to merge them manually.

  • 1
    Additional note: Run Migration Assistant at the first run of the newly installed OS, otherwise you end up with 2 accounts & have to merge them manually.
    – Tetsujin
    Aug 31, 2018 at 10:55
  • Thanks for the comment @Tetsujin. Can you please edit it into the answer.
    – Nimesh Neema
    Aug 31, 2018 at 11:20
  • @NimeshNeema surely that is up to you to edit that comment into your answer? Otherwise we could end up with answers being changed by people and the “I never said that” syndrome...
    – Solar Mike
    Aug 31, 2018 at 12:28
  • 1
    @SolarMike - tbh, I'm usually pretty easy whichever way round it works, so long as the info gets across. @ Nimesh - for future ref, I have no issue at all with anyone lifting a comment of mine into an existing answer, if it helps the overall structure of the answer.
    – Tetsujin
    Aug 31, 2018 at 12:56
  • I recently had to replace a laptop, and for reasons unknown, many app preferences did not get restored! Even weirder, keychain data in iCloud wer gone! I edited the answer to avoid this biting someone else.
    – WGroleau
    Aug 31, 2018 at 13:38

I assume you purposing making a Time Machine backup to a external third drive then use the Migration Assistant to restore from this backup. Another option would be to put the old drive in a shell and plug into a USB port. You could then just use the Migration Assistant to restore after a fresh install of macOS to the new SSD.

  • It’s quite possible that one would need a powered enclosure- I don’t know if the existing internal hard drive could be powered by USB only...
    – Tim
    Aug 31, 2018 at 16:26
  • @Tim: For example, this would be a possible SSD upgrade kit. This upgrade includes the enclose, which is powered from the USB port. Usually 3.5" HDD need a powered enclosure and this model Mac can not accommodate an internal HDD of that size. The drive in this model Mac plugs directly into the PCIe 2.0 x2 bus. Aug 31, 2018 at 16:45

I would recommend using Carbon Copy Cloner (https://sites.fastspring.com/bombich/product/ccc5) to create a bootable external drive with a recovery partition. Then you can replace the internal drive, boot from the external drive, and restore on to the new drive.

It is not free, but it is superior to Time Machine in some ways. (The two are really intended for different purposes.) Even if you can succeed in doing your current task with Time Machine, a more thorough backup solution has advantages for your future, if you have a disk failure.

Although TimeMachine can be used to restore a system, it assumes the existence of a working recovery partition on the hard drive. If the hard drive is corrupted or has died and that is not the case, then it won't work.

After CCC (Carbon Copy Cloner) backs up your drive, it asks if you want to create a Recovery Partition on the destination. This enables you to create an external drive with all the booting and recovery options as your internal drive.

So hypothetically, if you have created such an external drive, you could replace your internal drive with a bare, unpartitioned, unformatted new drive, and restore it to your previous internal drive's state using CCC. (You might need to partition it separately with Disk Utility, I'm not sure.)

In addition, having the CCC external drive would enable you to use your computer as you did before (though more slowly) until you could restore your internal drive back to working condition.


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