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macrumors 6502
Original poster
Jun 8, 2018
Manchester, UK
One question that I'm hopeful somebody in here may know the answer to. I use a Mac Mini (2018), and when it comes out I'm considering testing out Big Sur. I'd be looking to run it from a 128Gb USB drive which would be plugged into a USB3 hub. Is this feasible or would I need to buy a USB C drive and plug that directly into the Mac?


macrumors regular
Nov 29, 2014
You would need an external SSD. macOS is dog slow when run from a spinning hard drive.

One thing to keep in mind with the Mac mini is that the T2 firmware cannot be downgraded when something goes wrong.


macrumors 68000
Mar 16, 2011
Do they have like a 256 or 500gig SSD that you plug into a lightning port for the 2018 mac mini? I'd also like to try that and keep my 1 TB mojave. Is that possible?


macrumors 6502
Jul 17, 2002
Hello dbrewood,

I understand your excitement to try out the macOS Big Sur beta. I had entertained that thought also!

However, a casual search of the Macrumors forums indicates that it may not be worth the risk at this point in time.

For example, see

I personally would not recommend installing Big Sur right now. If you can't resist the temptation, you should
install Big Sur on a completely self-contained, non-critical system. If the install breaks the system, then you'll still be OK.

Good luck on your decision.


Darn...... so it looks like the only option will be to partition the hard drive on the Mini ..... ?


macrumors newbie
Mar 13, 2011
Second release installed directly on 2018 MacMini - no issues. Had to clear out some local snapshots to clear up HD space for install. SO far all good after 24 hours.
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