Using an external SSD to boot a 2018 Mac mini?

[Ubele]

Given the high price of storage upgrades for the new Mac minis, has anyone thought about buying a 128 GB base model and using a larger external SSD as the system drive? This has been a popular solution with people who didn't want to open their older minis to swap out the HDD or create a Fusion drive. The main reason to have a large system drive is that both iCloud and Dropbox need to be on the system drive to avoid synchronization errors. If you want a local copy of everything you have in the cloud, you need a system drive that's big enough to hold them. My current desktop Mac is a 2012 mini with a 2.12 TB Fusion drive. I just switched from Dropbox to the 2 TB iCloud family plan for my wife and myself. Eventually, I'd like to get a new mini for the 4K video support. I'm guessing that an external system drive would provide a performance hit, but it hasn't been that significant for people who have done it with their 2012 minis. 1 TB SSDs have really come down in price.

 

[redheeler]

I would use the fast 128 GB internal as the system drive, with a larger external (HDD or SSD) for file storage. But the real-world speed difference is less than the difference in specs or benchmarks, so an external SSD should work fine as a system drive.

 

[F-Train]

This might be helpful: https://forums.macrumors.com/threads/external-vs-internal-ssd-speed.2090138/

 

[Ubele]

I would use the fast 128 GB internal as the system drive, with a larger external (HDD or SSD) for file storage. But the real-world speed difference is less than the difference in specs or benchmarks, so an external SSD should work fine as a system drive.

Thanks - that's good to know about the real-world speed difference. A 128 GB drive wouldn't hold all the files I store in my iCloud Documents folder, though. You can store your iTunes and Photos libraries on an external drive, but you can't store your iCloud Documents folder on an external drive. I assume the reason is that iTunes and Photos use managed libraries that avoid synchronization errors, but the Documents folder isn't a managed library. I'd need a 512 GB drive to hold all my system files, apps, and iCloud Documents files. I have an external 1 TB SSD in a USB 3 enclosure, which would be fine for an external system drive. I'm in no hurry to get a new mini, but I'm thinking ahead about money-saving options.
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This might be helpful: https://forums.macrumors.com/threads/external-vs-internal-ssd-speed.2090138/

Thanks - that's helpful.