This week’s pleasant surprise with the launch of new Mac mini and Studio models, together with the first M5 Ultra and M6 chips, has also revealed Apple’s timetable for Golden Gate. As those new models start shipping on 22 September, the window for the first public release of Golden Gate has narrowed to 15-22 September, with greatest likelihood on the same day as the arrival of those new Macs. Early batches will come with a pre-release version of macOS 27 installed, probably based on the current seventh beta release, and they’ll most likely need to be updated immediately to version 27.0.1, which may also be the designation for a concurrent public release.

If you’re still undecided about ordering one of the new models, then be prepared for the shock of their 25% price increase. This Mac mini M4 Pro cost me £2,699 when I bought it on 8 November 2024, and a direct equivalent Mac mini M5 Pro now comes to £3,399.

I fear this price rise will force many to delay upgrading, particularly anyone coming from a mid-range Intel model. In some countries Apple is offering various schemes to soften the price rise, including its new Upgrade leasing programme. If you’re a business and looking to a high-end Studio to run LLMs locally, that’s an extremely attractive option now, and far cheaper than Apple Card finance. If you’re considering a business purchase, look carefully at all the options.

At the same time as the release of Golden Gate, we should get Tahoe 26.7 and Sequoia 15.8, but it looks increasingly likely that the final version of Sonoma has been 14.8.9, released on 6 August. Hopefully those two security updates will realign firmware versions with Golden Gate.

At the moment, Apple silicon Macs kept up with macOS updates should be running mBoot firmware version 18000.161.9 if they’re still on Sequoia or Sonoma, but 18000.161.10 if they’re on Tahoe. Golden Gate will leap ahead to something like 20457.1.29, and I’m hopeful that will be included in both Tahoe 26.7 and Sequoia 15.8 to keep them in sync with that single mBoot version.

There are only two ways that an Apple silicon Mac can have its firmware updated: either as part of a macOS update or install, or when a complete IPSW image file is installed when they’re restored in DFU mode, from a second Mac.

The rule when installing or updating macOS is straightforward. Whenever a macOS installer or updater is run on a Mac, even if it installs or updates a copy of macOS on an external drive, then that will update the Mac’s firmware to the version in that installer or updater, when that’s more recent than the version currently installed. The only common exception to this is installing or updating macOS in a virtual machine, which takes place in complete isolation from macOS in the host.

This can catch folk out when they install a beta to an external drive, for example. If your Mac has macOS Sequoia 15.7.9 installed, its mBoot version will be 18000.161.9. If you then install Golden Gate to an external drive, that will update your Mac’s mBoot version to 20457.1.29, for example, and that will remain until you install or update a version of macOS that brings a higher mBoot version. The only way to downgrade its firmware would be to put it into DFU mode, connect it to another Mac, and install an IPSW for an older version of macOS.

Running an older version of macOS with newer firmware shouldn’t bring any problems, indeed it’s standard for the two older supported versions of macOS.

That’s different from the Recovery system, run when you put your Mac into Recovery Mode. That’s installed on a Recovery volume paired with its System volume, so your Mac will have one Recovery system for each boot volume group it has installed. If it has just been running in macOS Sequoia, and you then start it up in Recovery, that will use the Recovery system that’s paired with its Sequoia System volume.

Finally, if your Mac is still running Sonoma and you want it to have continuing security updates, time is running out. You now have less than a month to upgrade to the next version of macOS you have chosen.