A fraught few hours: migrating to my new iMac Pro

I finally cracked, gave in, and bought an iMac Pro. Only the base model, as I figured paying nearly £/$/€ 5000 for a Mac these days was quite sufficient, particularly after I had also upgraded to an iPhone XR. Yesterday was Migration Day, and got off to a very bad start.

We don’t have a clue how many iMac Pros Apple has been selling, but they don’t seem to shift like hot cakes. My iMac Pro was bought from stock at one of Apple’s larger provincial stores in the south of England (Southampton), and came with macOS High Sierra 10.13.2 pre-installed. That was released on 6 December 2017, eleven months ago, a week before the first iMac Pro shipped. That suggests that this iMac Pro, sold in mid November 2018, may still be from the original production run.

Apple has made everything about the iMac Pro special, not just its extraordinary price. Unboxing it immerses you in some of the best-designed protective packaging that I have come across, not just some blocks of expanded polystyrene. In its protective cocoon, each iMac Pro looks set to withstand being dropped from the back of the delivery truck, yet that protection drops away when you come to unbox it.

It was when I started my iMac Pro up that things began to turn sour. I guessed that it would need a macOS update, but given the huge gulf between its macOS and that on my old iMac, it couldn’t even attempt to migrate my files, apps and settings. I didn’t realise how old its installed macOS was until it had configured without migration, when I could look at About This Mac.


By then it was too late: my Mac was hell-bent on syncing to iCloud, downloading the High Sierra 10.13.6 update which I didn’t want, plus another few GB of app updates. When I tried to download the Mojave 10.14.1 installer from the App Store, all my bandwidth was gone. Time to download: 9 hours 25 minutes.

I recalled that I had a complete 10.14 installer and the standalone 10.14.1 updater, so located those and copied them onto the iMac Pro with great relief, until I tried running the former.


After a couple of minutes thinking about it, the Mojave 10.14 installer decided to throw an error. And it did a second time too.

By now, setting this expensive new Mac up had taken me an hour, and apart from syncing with iCloud and being part-way through some unwanted updates, neither I nor the Mac were any further forward. I had wasted a lot of time while it had tried to migrate when it should have known it couldn’t, and now I couldn’t apply the macOS update which I needed to be able to migrate. Many others who had just paid £/$/€ 5000 might at this stage be calling Apple for a refund.

It was then that, quite fortuitously, I discovered that I could run my 10.14 installer if I opened it using the Open button in the App Store. This still puzzles me, because that installer was the original for 10.14, and that offered by the App Store is currently for 10.14.1. It was now getting close to lunchtime, and my iMac Pro was finally starting the upgrade to Mojave.

What you get for your £/$/€ 5000 is wickedly quick. It’s my second Mac with eight cores (the previous being one of the ill-fated Mac Pro 8-cores from over ten years ago), and it was hugely relieving to see the install progress bar passing time so fast, for once. It came up to 10.14 blissfully quickly, and by the time that I was eating lunch, was well on its way to 10.14.1.

I knew that, when I finally got to it, migration from my old iMac would take a while. I was squeezing a quart into a pint pot: the 2 TB Fusion Drive in that iMac had 1.3 TB used, but my iMac Pro has only the standard 1 TB internal SSD. Two folders – ~/Documents and ~/Pictures – account for around 700 GB of my iMac’s storage, so I had moved those out onto an external 1 TB SSD. This left rather less than 500 GB to be migrated.

I had also chosen to provide the fastest conduit for that migration: my two Macs were connected back-to-back by their Thunderbolt ports. Admittedly the old iMac could only offer Thunderbolt 2 [thanks to my son for correcting this], but at least Apple’s adaptor was happy to get the best out of it.


The Migration Assistant, doing most of its work on the iMac Pro, was fairly quick. Transfer speeds started very dissappointly at around 10 MB/s, which even for Thunderbolt 1 would seem fairly dismal. But as it got onto some of my larger files, they steadily climbed to 60 MB/s. Over 600,000 files taking rather less than 500 GB were carried across in around two and a half hours.

The Migration Manager in 10.14.1 also seems very effective: little had to be left behind, but I haven’t yet found anything on the iMac Pro which is causing problems.

So here I am, nearly five turbulent hours later, with the black iMac Pro almost invisible in Dark Mode, words and images seemingly suspended in space. This feels like a very very special Mac, but then so it should.

What does Apple need to change? Most importantly, its engineers need to look closely at the chaos that erupts when trying to set up a brand new Mac which has shipped with an almost year-old macOS. The user needs to be informed early during the setup process, so that they know not to waste time trying to migrate, which is doomed from the start.

During that first setup, macOS needs to make one simple call to Apple, to determine what the current release of macOS is. When it is different from that pre-installed, the setup process needs to offer that update as a first and sole priority. Forget loading iCloud and intermediate updates, the user needs to get up to the latest macOS as quickly and simply as possible. Then they attempt to migrate, which should greatly reduce nugatory updates.

It’s not that this situation is unusual now. With such frequent updates to macOS and iOS, most new purchases are delivered with an OS which is already well out of date. That even applied to my iPhone XR, but that story is for another time.

One final puzzle: once I had completed migration, one of the first apps that I ran, largely out of curiosity, was LockRattler 4.16. It crashed when trying to start up the first two times that I ran it, perhaps because it couldn’t get a connection to verify its notarization (I was also having Ethernet issues at the time). Ever since then, it has run fine. So if you find apps like LockRattler crashing on startup, don’t toss them in the Trash. Wait until your Mac is a little more stable and better set up, and they will probably be fine again.

As for me, I feel like a short holiday now, well away from computers.