Format SSD to APFS, which drives?

Hello, I’m currently learning about SSD and APFS, by continuing education with Taking Control Books, and Carlson recent videos. I’ve yet to find Web sources, even manufacturers, which confirms SSD compatibility with APFS formatting.

Yesterday, I unpacked a new SanDisk Extreme 1 TB, only to find out that it would not format to APFS. The only thing that I neglected to do was to set Mac Utility Disk to view all devices. Anyway, I’ve already returned the SanDisk to my local computer retailer. About a month ago, or so, I had a positive experience with WD My Passport SSD. Next time, how do I determine which SSD is capable of APFS format? Thanks.

I have and have had several SSD of various brands and have never come across one (or an HDD) which could not be formatted APFS.

And, in many cases, formatting new drives has been a problem for Disk Utility. Erasing a drive to GUID/HFS+ often lets Disk Utility carry on. Also, diskutil (in Terminal.app) seems to work every time. I make a shell script to format backup drives with HFS+ partitions and let Carbon Copy Cloner do magic to make APFS where needed.

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Interesting. I can’t imagine what about a drive would prevent APFS formatting. At its core, every SSD is just a block storage device. The OS reads and writes 512 byte blocks based on whatever organization the software wants.

I think the biggest potential issue here might be the partition type. Unless things have changed recently, I think you can expect most devices (especially those 2TB and smaller) to come pre-formatted with an MBR-style partition table. This is because MBR is compatible with any device up to 2TB, and old PC operating systems (e.g. Windows XP and older) can’t support other partition types.

Apple’s file systems (HFS and APFS) are incompatible with MBR-type partition tables. Well, they could probably be made to work with them, but Apple has never done so. If your device ships with an MBR partition table, you need to blow it away and replace it with another. These days, that would be a GUID partition table (GPT). A drive that needs to be compatible with old Macs (and we’re talking PowerPC or older) should use the now-deprecated Apple Partition Table (APT) format and format partitions as HFS+.

Drives larger than 2TB probably come pre-formatted with a GUID partition table, because neither MBR nor APT can support drives larger than 2TB.

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I’ll go out on a limb here and say that all SSD’s are APFS compatible. Specifically, I have two 1TB SanDisk Ultra II’s that have been APFS formatted since High Sierra was released as well as Samsung and LaCie drives. Agree with James and David that you probably didn’t initially erase them with GUID partition format.

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Thanks, I didn’t have GUID as an option. Robert

Not sure what macOS you were using at the time, but it’s been available since High Sierra, although not always obvious how. See https://www.macobserver.com/tips/quick-tip/how-to-format-drive-guid/.

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I use Catalina. Utility Disk did not offer scheme options. Robert.

For Disk Utility under Catalina:

  1. Select View->Show All Devices not Show Only Volumes

  2. Select the Volume you wish to format

  3. Select Erase and you should then see a Scheme drop-down menu. The menu does not appear if you select the Only Volume view.

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Drives in enclosures like to come with weird Windows tools or instructions to download software. Pfft. I’ve never gone that route. You can get a decent SATA USB 3.1 dock for $35 that will accept any kind of 3.5" or 2.5" drive. From then on I just get a bare drive and swap whenever I please. That way I choose the exact drive I end up using. I’d never order drive and enclosure together. Ever.

Although I doubt the enclosure was the issue here, I do agree with Simon that bare drives and a dock are the best answer for externals and the approach I have been using for many years now. The only enclosed SSD I ever bought was the LaCie that I found on sale for less than a comparable SSD.

A lot longer than that. The ability to format and boot from GPT-partitioned drives was introduced with the first Intel Macs, because that’s when Apple switched from OpenFirmware to EFI. That would be since Mac OS X 10.5.

The specific GUI dialog in Disk Utility has changed over the years, but the feature has definitely been present since then.

The important thing is that you need to erase the drive, not the volume.

A volume is a region of the disk defined by the partition table and other related structures. As such, nothing you do to a volume can affect the partition table. If you perform an action (like erase) that acts on the entire drive, then you should see options that affect the partition table (e.g. select the table type, create/destroy/resize volumes, etc.)

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CCC link:
https://bombich.com/kb/ccc5/choosing-backup-drive

Just a point on CCC’s advice. I think some of CCC’s options here especially for SSDs are very out of date. He only mentions a hard-to-find non-mainstream brand (“Oyen Digital” SSDs; who??), yet has no comment on anything more up-to-date and relevant to most users buying decisions.

For example, unfortunately he doesn’t talk about any Samsung 2.5" SATA models that are hugely popular due to their increasing affordability (eg. “QVO”-series).

QVO 860-series has been released years now, up to 4TB options at a doable $£€400 (100 per TB):

QVO 870-series with virtually same performance has been released ~a month, with a new 8TB option $£€800 (100 per TB):

Strange.

Thanks, Simon, for that particular “sans enclosure” info, which I’ve not found recommended online or in any book, friend, or salesperson (perhaps obviously). Perhaps I’m looking in the wrong places or need a better class of friends. This is why I subscribe to TidBITS: to learn what fellow geeky comrades were using. The marketplace effectively dumbs us down. Thanks again, Simon and Al Varnell.

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