Using Thunderbolt storage as Windows startup disk

[Taj Armstrong]

Hi guys,
I'm using a 2014 iMac Retina with a 1TB Fusion Drive. I like to upgrade my Mac to include more than 120GB of SSD storage, so at first I looked at replacing the internal hard drive. The 68-step iFixit guide mat it seem like a pretty risky procedure, and I'm now wondering if you can use external Thunderbolt storage as a startup disk for macOS as this might be the solution I'm looking for. Is this possible, and if anyone's done it what's your experience with it? Are there any SSDs you'd recommend (looking for something in the 2-3TB range).
Thanks,
Taj Armstrong

 

[weckart]

I run my 2011 iMac using an external TB SSD drive as the startup disk with another TB SSD on the other port. If I can get a decent deal on an SSD drive this Black Friday, I shall replace the internal hard drive so that all my drives are SSD.

Part of the reason is unless I put my iMac into deep sleep, it wakes up from normal sleep every minute or so and starts up the internal hard drive only to spin it down seconds later. Very annoying. Even ejecting the internal hard drive doesn't put a stop to the spin up/down problem.

 

[ActionableMango]

I'm now wondering if you can use external Thunderbolt storage as a startup disk for macOS

Yes you can use an external disk to boot MacOS. Strangely though, your thread title asks if you can use Windows, and that's a different situation altogether. Windows does not like to boot from an external disk, although there are complicated ways around that.

I run my 2011 iMac using an external TB SSD drive as the startup disk with another TB SSD on the other port. If I can get a decent deal on an SSD drive this Black Friday, I shall replace the internal hard drive so that all my drives are SSD.

Part of the reason is unless I put my iMac into deep sleep, it wakes up from normal sleep every minute or so and starts up the internal hard drive only to spin it down seconds later. Very annoying. Even ejecting the internal hard drive doesn't put a stop to the spin up/down problem.

I doubt the computer is waking up because of the hard drive. Far more likely the reverse is true--that the hard drive is spinning up because the computer has woken up. Every time the computer wakes from sleep, it adds the "reason for wake" to the system log. (In fact, the hard drive is probably spinning up so that the computer can update the log file!) So instead of speculating you can just look at your log to determine what is actually waking the computer up.

http://osxdaily.com/2010/07/17/why-mac-wakes-from-sleep/

 

[Taj Armstrong]

Strangely though, your thread title asks if you can use Windows, and that's a different situation altogether. Windows does not like to boot from an external disk, although there are complicated ways around that.

Whoops, forgot to change that – I was originally going to ask about Windows but I figured it would be easier to have Windows on the internal drive and macOS on the external drive if possible. The reason I had this question is the first place is that when I dual booted Windows using the fusion drive it would use the slower hard drive portion instead of the SSD portion and I wanted to use some heavier programs on Windows that didn't perform very well on the hard drive. Hope that makes sense!

 

[ActionableMango]

I figured it would be easier to have Windows on the internal drive and macOS on the external drive if possible.

Yes that's the right way to do it. Getting Windows to install and boot on an external drive is a big effort.