macOS and/or Windows on external SSD (2020 iMac with T2 chip)

[miretogo]

On a former iMac of mine I tried to install Windows 10 on an external SSD but discovered that W10 doesn't allow it - apparantly it due to licensing reasons. In contrast, installing macOS on the external SSD did work. However, now that the T2 chip has arrived in 2020 iMacs, is installing macOS on an external SSD still possible (without a hassle)?

If it is, I would install W10 on the internal SSD and macOS on the external SSD.

If it is not, I would create two partitions on the internal SSD - one for macOS (and macOS apps) and one for W10 (and W10 apps). I would also create two partitions on the external SSD - one for macOS data and one for W10 data. By the way, TimeMachine can include external drivers in backups:

How to make sure Time Machine backs up external drives

A reader wants to shift his Photos and iTunes libraries to an external drive and ensure they're backed up by Time Machine.

www.macworld.com

 

[pldelisle]

See About Startup Security Utility

If external, chose a Thunderbolt enclosure. Will be a lot faster than USB based enclosure since the OS will run on it.

 

[miretogo]

Thank you. So booting macOS from an external SSD is still possible, although it requires changing the respective setting in the Startup Security Utility.

Using Thunderbolt is faster but also so much more expensive that I don't find it worthwhile.

PS: For example, a Samsung Portable SSD T5 with 2 TB of storage currently costs "only" about 230 € right now.

 

[pldelisle]

Thank you. So booting macOS from an external SSD is still possible, although it requires changing the respective setting in the Startup Security Utility.

Using Thunderbolt is faster but also so much more expensive that I don't find it worthwhile.

PS: For example, a Samsung Portable SSD T5 with 2 TB of storage currently costs "only" about 230 € right now.

Yes it's more expansive, but the way the bus works make it more stable than USB. It's a connectivity made for moving data a lot.

If you really not want Thunderbolt, at least take a USB 3.1 Gen 2 enclosure. You have 1/4 of thunderbolt performance (10gbps theoretical max).

 

[CheesePuff]

Thank you. So booting macOS from an external SSD is still possible, although it requires changing the respective setting in the Startup Security Utility.

Using Thunderbolt is faster but also so much more expensive that I don't find it worthwhile.

PS: For example, a Samsung Portable SSD T5 with 2 TB of storage currently costs "only" about 230 € right now.

Look at the Samsung T7, its not too much more expensive and is roughly double the read and write speeds of the T5.

 

[miretogo]

Thanks for poining that out, I didn't know that. However, where I live, the T7 is currently about 70% more expensive thsn the T5.