slow Mac OS 12.6 update

Hi there bebe_hilly,

We're happy to help. The amount of time it takes to update macOS is directly dependent upon the strength and reliability of your network connection and the size of the update itself.

If you're installing macOS, the Apple logo or progress bar might persist for much longer than usual. As installation continues, the progress bar might move slowly and pause for long periods. That's why Apple recommends beginning macOS installation in the evening—so that it can complete overnight, if needed.

If you've attempted to let the update complete overnight, and it still seems to be stuck or running slow, try these steps:

If your Mac is stuck on this screen

If you think you've waited long enough to know that your Mac is stuck on this screen, follow these steps.

1. Press and hold the power button on your Mac for up to 10 seconds, until your Mac turns off. (Every Mac has a power button. On notebook computers that have Touch ID, press and hold Touch ID.)

2. Turn your Mac back on. If the issue persists, press and hold the power button until your Mac turns off. Then unplug all accessories from your Mac, including printers, drives, USB hubs, and other nonessential devices. You could have an issue with one or more of those devices or their cables. 

3. Turn your Mac back on. If the issue persists, once again press and hold the power button until your Mac turns off. Then follow the steps in this article: How to repair a Mac disk with Disk Utility. It explains how to start up from macOS Recovery so that you can use Disk Utility.

- If Disk Utility found no errors, reinstall macOS.

- If Disk Utility found errors and repaired them, restart your Mac. If the issue returns after restarting, reinstall macOS.

If you still need help, please contact Apple Support.

You'll find this information here: If your Mac starts up to an Apple logo or progress bar - Apple Support

Take care.

The speed of the update depends some on what you are updating from. For instance, if you are updating from El Capitan (10.11), it will take a long time, the update across many MacOS versions is complex and the drive must be recast as APFS (from HFS+). This could take hours.

If you are updating from 12.5 to 12.6, my experience with three Macs (all Intel Macs) is that is takes 30-45 minutes, except for the work Mac which has mandatory anti-virus, it took longer on that one. During the update the Mac can appear to hang, the "minutes remaining" sometimes stops updating for a while, and the Mac goes black and stays that way for over a minute or two, which leads some people to think things have stopped working. But these things are all normal, I've seen it on multiple Macs.

I think if the update ran for over 3 hours and showed no sign of progress, I would begin to think it was not working.