I recently upgraded from a 2017 5K iMac to an M4 iMac. I would like a Mac of similar vintage around for legacy compatibility. But my iMac is large and heavy for occasional use. I would therefore like to consider a 2018 Mac Mini, and be able to pair it with a very small monitor, the priority being a compact setup.
However, I have read that it is impossible to downgrade later 2018 Mac Minis that shipped with Catalina or Big Sur to Mojave. Is this true? I wouldn’t want to spend money on a Mini, only to find that Mojave compatibility is blocked.
A second question: Is there a better source than eBay to find a Mini these days?
Generally speaking, the current OS at the time new hardware is released, is the oldest OS that will run on it. Mojave was released in September 2018, while Catalina was released in October 2019. If the Mac mini you want to purchase is one of the Late 2018 models, which were released in October 2018, then it should be able to run Mojave.
Small Dog Electronics in Vermont has been a good source for refurbished Macs for many years, but it looks like they don’t have any pre-owned minis right now:
Thank you! I would definitely want one of the 2018 Minis. The only trouble is that some of the information that I found seemed to imply that 2018 Minis sold from 2020 onward could not be downgraded, despite the stated minimum OS of Mojave. I’m suspecting (and hoping) that to be misinformation, since what you say generally comports with my own past experience.
Well, the next model of Mac mini was released in November of 2020. That one had an M1 processor, and the minimum OS should be Big Sur. But any of the Late 2018 minis sold earlier in the year should be able to run Mojave. If they were sold with Catalina pre-installed from October 2019 to October 2020, they should be downgradable. Might need to create a Mojave installer on a USB flash drive, boot the mini from that drive, and use it to erase the internal drive and install Mojave.
I’ve occasionally seen remarks that firmware updates can prevent or interfere with system downgrades. Firmware updates occur normally as part of the macOS installation process.
At least with Intel systems, I don’t recall ever seeing speacific information about which type of system failed to downgrade and the versions of macOS in question. If it were a significant phenomenon, I’d expect details to be much more widely known and publicized.
Consquently, I would put rumors that Mac firmware updates can prevent macOS downgrades in the category of folklore, not facts, at least for Intel machines.
I think the other major source of statements that an Intel Mac can’t be downgraded after being upgraded is in reference to downgrading from a newer operating system to an older one directly while preserving third party apps and user preferences and settings. However, you can downgrade from a newer operating system to an older one if you boot into Recovery Mode, erase the drive, and perform a fresh installation of an older OS. If you have a Time Machine backup of the older system, for example, you can restore from that.
In your case, if your 2017 iMac was running Mojave, make sure you have a good Time Machine backup of the 2017 iMac, and then you can use it to restore your files and preferences to a 2018 mini running Mojave. There are lots of “how to” guides on the net for that scenario. Depending on exactly what you want to accomplish, it may be easier to start from scratch by installing Mojave and then manually installing third party apps, etc.
One other comment/suggestion: consider installing Mojave in a virtual machine. I’ve found it convenient to run legacy versions of macOS in virtual machines on Intel hardware. As long as your host machine has enough RAM, performance can be quite good, and running a virtual machine makes it easy to move to another Intel Mac if you ever need to. No matter what, be sure to make regular Time Machine backups of your “new” Mojave system.
This is an important difference: Apple silicon Macs can downgrade their firmware. Intel Macs cannot.
It is conceivable that a firmware update could render issues on an Intel Mac with a later OS downgrade that ends up pairing an older OS with a newer firmware that cannot be downgraded to be in sync with the OS’ vintage. However, I have never encountered such a situation myself.
Exactly. I don’t know of any verified cases of macOS downgrades actually being prevented or even rendered unstable on Intel machines. Absent verified cases, the issue is conceivable, but highly unlikely.
If it did happen to someone, I’d wager that something else was the root cause, not the firmware update itself. No doubt there’d be a detailed article about it here on TidBITS if it were an issue.
One of the reasons I bought a 2018 Mini was so that I’d have a Mac that could run 32 bit apps (using Mojave) into the future.
The 2018 Mini is STILL on the back table, and still runs Mojave just fine. I also have an external SSD with Sequoia on it, and can boot from that as well. But running a newer version of the OS has no affect on its ability to boot Mojave (even after a firmware upgrade).
I’d recommend 16gb of RAM and at least 512gb of SSD (1tb is better).
I kept around my trusty old late-2013 13" Core i7 MBP for exactly that reason. And it ran great on Mojave all the way up to essentially now.
Last week I noticed that it was wobbling on my bench at the lab I had it in. At first I thought there was something lodged underneath it. Then I realized it was wobbling because the bottom case has started bulging to the point where not all 4 feet are making contact with the table. Argh. Battery is toast. Now it’s gotta go — I don’t want to be the guy that started the fire that burned down half the campus. Just need to figure out how to thoroughly wipe its SSD first. Come to think of it, easier might just be to remove the SSD before I hand the MacBook over to Apple so it can burn down their store uhm, be recycled.
Will Apple take a device with a swollen battery? I recently tried to recycle an old tablet that had a swollen battery. Best Buy–my go-to for recyling–would not take it.
FYI, the Wikipedia article for the Mac Mini specifically states (in it’s technical specification chart) that the 2018 Mac Mini will run Mojave (under Operating System/minimum)
I’m in a similar situation to you – I just upgraded from a 2017 Intel i7 iMac to a M4 Mac Studio; and I, too, wanted to have something for running a few Intel applications on. I purchased a refurbished unit from OWC; seems to work fine with Monterey and Sequoia (the latter is the final macOS version the 2018 Mac Mini can run).
I haven’t tried Mojave yet (several other projects taking up all free time), but I hope to install it, and port over programs from my old Intel iMac. I’ll post here when I do.
You have my sincere commiseration, Simon! Your situation is exactly why I opted for the Mini vs a MacBook of any kind. Solid-state batteries can’t get here fast enough!
I’ve bought third-party batteries for years for my collection of vintage Macbooks. Yes, you still have the problem of disposing of the old swollen one. My county has a twice-a-year elecetronic recycling event that takes pretty much anything - maybe worth looking into in your area.
Since I don’t yet know which OS my new Mini will ship with, it’s possible that I may need to follow the steps linked above to create a bootable installer. Thank you again for that link!
Is this something I could easily do on my mom’s 21.5-inch iMac of the same vintage? It’s running Monterey. Is that a wrinkle that would mean it’s a better idea to create the bootable installer on my old Mojave iMac before erasing it, or does that matter at all?
I would create the bootable installer from the old iMac, if possible. I have this on a memory stick which is fortunate when my 2015 iMac suddenly died. I could set up a refurbished 2017 iMac as a replacement.
Just need to figure out how to thoroughly wipe its SSD first. Come to think of it, easier might just be to remove the SSD before I hand the MacBook over to Apple so it can