What format for External Hard Drive for Photoshop scratch disk

[j9lemmon]

I have a 9 month old Western Digital My Passport Ultra for Mac 2TB, which came formatted Mac OS Extended It is not showing up when I try to set it as my scratch disk for Photoshop 2024. Another post recommeds reformating an External Hard Drive to APFS, but I'm reading that APFS works best on SSD  and my External Hard drive is not solid state; I read that APFS operates poorly on spinning disks and wears them out.

But my Photoshop files tend to be fairly non-complex and I use Photoshop sparingly, so will APFS work okay?

Or is theire another file system I should re-format to?

Thanks for any advice.

[j9lemmon]

So I went ahead and re-formatted my External Hard Drive to APFS.

Photoshop 2024 still does not recognize it in the Scratch Disks setting. All I see is my Mac HD. I cannot un-check it.

So Photoshop 2024 isn't recognizing my Western Digital My Passport Ultra External Hard Drive whether is formatted to APFS or Mac OS Extended.

Could there be another reason beside file format?

[Kevin Stohlmeyer]

@j9lemmon how are they connected to your Mac? USB-A, Thunderbolt, etc.

[j9lemmon]

@Kevin Stohlmeyer My WD External Hard Drive is connected via Thunderbold port.

I can save a Photoshop file to the External Hard Drive.

[Conrad_C · Accepted solution]

The Adobe article about Photoshop scratch disks says that APFS or macOS Extended are both supported, so either should have worked. I’m not sure what the cause of the problem might be, just mentioning that it seems to be something other than the format.

I’m using an external SSD in a generic enclosure, and that works as a scratch disk. I can’t think of why a very common WD Passport wouldn’t work, if it’s plugged into a standard USB port. I would only note that, if it’s a hard drive, it would not be a fast scratch disk option. But it seems like it should at least work.

[j9lemmon]

Interestingly, I did a little work in Photoshop today, 3 days later, and now my External Drive shows up and I'm able to select it as the scratch disk.

No idea why it works now and didn't 3 days ago, but I'll take it. 

Thanks for the suggestions.