"Delta" upgrade from Monterey 12.6.2 to Ventura or download full installer from the App Store?

Delta upgrades are a good thing and result in a much faster installation. In some cases 5min instead of 45min to an hour. They are safe to use and you are likely to not even be prompted for your admin account password which is also a new feature that applies to Delta upgrades.

The concept was taken from iOS / iPadOS and greatly reduces the update size as it only needs to download the necessary differences from your installed base operating system. The base system is locked by Apple as immutable (meaning it cannot be changed). The System part of macOS is read-only as well as snapshot to APFS in a signed and sealed manner. The operating system boots from that snapshot. The gray entry is the read-only volume on disk which is the source of the snapshot.

Because the base OS is known good as it's impossible to tamper with it. Apple will be able to apply the Delta changes to it thus resulting in a much smaller download and shorter installation time.

Me, myself and I on an M1 Mac mini and on a 14" M1 MacBook Pro. Both upgraded to 13.1 in about 5min. Not counting download time. Subsequent betas updating fast too. It went so dang fast, I thought it might have failed. But nope. It worked.

Many people didn't upgrade from Monterey 12.6.1 to Ventura because 12.6.1 came out the day Ventura came out. If you didn't have Monterey 12.6.1 you didn't get the Delta update. The capability shipped with Monterey 12.6.1 and Ventura 13+.

Subsequent Ventura updates have been very speedy for me in comparison to the 45min to an hour previously. Certainly, it may take more than 5min but it's still going to be faster than the alternative. Different Macs may have different performance characteristics plus networking. I am sitting on a Gigabit Internet connection using Ethernet and this M1 Mac mini and the 14" MacBook Pro both have extremely fast internal SSDs. I upgraded my wife's 2017 iMac with a 256GB SSD and that took about 15min.

12GB non-delta download via Terminal softwareupdate --fetch-full-installer --full-install-version 13.1

completed in 5m48s. The installation time was approximately the same.

Internet speed matters but sometimes Apple CDN servers are slow due to heavy traffic.

Automatic updates, download the delta behind the scenes before it pops up and tells you there is an update pending that will install overnight unless you choose to install now.

Content caching helps quite a bit if you have several similar Macs as the download is cached on one Mac and delivered on local LAN to the others.

James Brickley wrote:

12GB non-delta download via Terminal softwareupdate --fetch-full-installer --full-install-version 13.1

completed in 5m48s. The installation time was approximately the same.

5m48s + 5m48s = 11m36s. 11m36s > 5m. Which is why I asked who you knew that upgraded in 5m. Glad that's sorted. 🙂

It's fine to upgrade from Software Updates. The 3.97 number is just the setup file. The rest will download from the internet.

James Brickley wrote:

Delta upgrades are a good thing and result in a much faster installation. In some cases 5min instead of 45min to an hour.

Who do you know that upgraded to Ventura in 5 mins?

James Brickley wrote:

Me, myself and I on an M1 Mac mini and on a 14" M1 MacBook Pro. Both upgraded to 13.1 in about 5min. Not counting download time.

FWIW, the download time counts. 😎