Why do mac os updates take 40 minutes nowadays?

[iBug2]

It took almost 40 minutes on my 2017 iMac 5K which has a really fast SSD. I remember OS updates taking 5-10 minutes even when SSD's were not this fast.

And it takes even less time to simply install the OS on an empty disk.

 

[Juicy Box]

I have also noticed that MacOS updates seem to be taking a lot longer than they used to.

I used to complain about Windows updates, and how long they would take, but it seems like MacOS has gotten almost as bad.

 

[Ritsuka]

Because they are big updates (3 GB), and probably Apple added some additional validations to validate the updates.

 

[yurc]

In past recent years, Apple ships update with firmwares updates for some Macs, that’s explain why it took longer for updates. Just one of probability though. Unlike regular software updates, firmware are permanently written to logic board and hence more taking time, writing, verification of firmware, etc.

 

[iBug2]

Because they are big updates (3 GB), and probably Apple added some additional validations to validate the updates.

Yes they are big but not as big as the OS itself. Like I said, clean installing the OS even takes less time.

 

[CTHarrryH]

It always took around that long for me.

 

[klaasjanb]

I think it's related to the switch to the APFS filesystem. According to some the new filesystem snapshot functionality is used to create a recoverable image in case the system upgrade results in a broken system.
Filesystem snapshots are not free though, which means more safety = slower update.

 

[TETENAL]

Filesystem snapshots are not free though, which means more safety = slower update.

APFS filesystem snapshots should be practically free. I doubt that's the reason for slow updates.

 

[klaasjanb]

APFS filesystem snapshots should be practically free. I doubt that's the reason for slow updates.

Making a snapshot is pretty cheap, but writing to a snapshotted volume and integrating changes can be a lot more expensive.

 

[ScreenSavers]

They are massive and take forever, since El Capitan , and maybe even Yosemite. It seems like on my 16 inch MacBook Pro, it estimates it will take 50 minutes but in reality it takes about 20. Still seems to long to me for a machine with 32GB RAM...

 

[zorinlynx]

It can take some time, because the update process has to be verified. An unbootable system means a trip to the Apple Store and tech time used, which is expensive. Now multiply that by thousands of failures... Not good! You have to be 100% sure the update succeeds.

This is an example of a typical update path:

1) Clone OS partition.
2) Write update to cloned OS partition.
3) Verify updated cloned OS partition.
4) Boot from updated cloned OS partition.
5) Mark old OS partition for deletion.