Which File Format to Use with External SSD?

Per this post, I purchased a new external SSD.

I’m sorry to ask a dumb question, but which of these two file formats should I use? I’m an M1 Max MBP.

None of these. APFS, if you do not need to use the drive with any Windows machines.


Sorry for my lack of tech knowledge here, but do I even need to format it? Do you know if Time Machine will just back up to it once I point to the drive? I don’t want to mess this up. :grinning:

TM is going to reformat it anyway IIRC.


Everything you need to know.

APFS is actually the preferred format for Time Machine backups, but TM backups will use an entire volume (and yes, as pointed out above, TM should offer to reformat the drive). If that’s not what you want to do, you can use Disk Utility to create two or more volumes and let TM use one of these, keeping another volume for your use.



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Thanks for the help. The new SSD is formatted and I have everything backed up to it and another older SSD in another location.

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Now that you have it set up, next time just use a hard drive. :stuck_out_tongue: SSDs are coming down in price, but the more room the better for a TM disk. Plus speed really doesn’t matter. Unless you don’t care about that kind of thing and don’t mind paying the SSD prices, then disregard.

The SSD is replacing a large external hard drive, which was going bad. SSD’s tend to have a longer shelflife and are more reliable, which is why I decided to go that route.:slightly_smiling_face:


I have the same drive and works fine. Easy to format for TM backups and fast. Good choice

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