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How to Erase and Factory Reset Your Mac
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Correct... this gives you the same end result as the old wipe/erase and reinstall OS routine.
What about Intel Macs that lack a Secure Enclave? FileVault should still do the trick but I'm not sure.
Nope.
Not for Apple chips and T2 intel hardware. It's just like in iOS: wiping user data and deleting encryption keys. And this is obvious as boot loader is on SSD and there is no external firmware chip. Everything is on SSD. Erasing all partitons (system and hidden) would prevent Mac from booting.
To do a proper factory reset you need another Mac + Apple Configurator app + DFU mode + downloaded IPSW macOS restore image.
This will create all necessary partitions and firmwares.
Then you will have booting screen just like in an out of the box machine.
Not for Apple chips and T2 intel hardware. It's just like in iOS: wiping user data and deleting encryption keys. And this is obvious as boot loader is on SSD and there is no external firmware chip. Everything is on SSD. Erasing all partitons (system and hidden) would prevent Mac from booting.
To do a proper factory reset you need another Mac + Apple Configurator app + DFU mode + downloaded IPSW macOS restore image.
This will create all necessary partitions and firmwares.
Then you will have booting screen just like in an out of the box machine.
If one used Filevault, the data cannot be recovered as was warned of earlier).
As long as you are using a T2 Intel or Apple Silicon, this is completely false. All data is encrypted at rest, even without FileVault enabled. When you invoke EACS, one of the functions is to clear the encryption keys from the Secure Enclave. Unless the buyer has access to a government level super computer, they will not be able to recover the data.
In fact, using Secure Erase will just make the SSD wear out faster.
Don't even need to enable FileVault. Since T2 & M series computers encrypt data by default, it all encrypted from day 0. All FileVault does is add a wrapper for the encryption keys based on your password.
That was my question too. I think the answer to “… just to go back to a clean state” may be further down in the article where it states:
“The following steps show you how it's done. Whether you simply want to start fresh with your Mac or are planning to sell or gift your computer to another person, after erasing it using this option, your Mac will display the Setup Assistant and be ready to be set up like new.”
I use Migration Assistant over wifi to transfer files to my new Mac. Then, I reset my old Mac for sale or trade using the method described. I don’t do a Time Machine backup because it seems to work for me without doing one. I also don’t have a large enough external SSD. Hopefully, nothing happens with Migration Assistant, but I think my files are in iCloud anyway for easy retrieval. I truly only care about my photos.
but does this process also clean installs the lastest OS version? ex) you had OS version 14.0 and if you do this restore step does it clean install to the current OS version 15.1 or does it just restore to factory 14.0?
I will wipe all data and settings and leave whichever OS version you had before the erase. It does not reinstall the OS.
Also noteworthy is that there are now two partitions one for the OS and the other for Data. I wouldn't be surprised although i'm no software engineer where a new version of macOS formats the target OS partition and installs a brand new version over it. Once Apple went this route, I quit doing clean installs. There's really no need and the OS will tell you if there's a problem inside the System's OS partition because it generally begins an internet restore.
Close, but not quite. This process does not touch the "System" partition. That is a sealed and signed partition. When you boot your Mac, the System Volume is actually as a disk image and can't be written to. All data is written to the Data partition. APFS does some magic behind the scenes to make it appear that the System volume and Data volume are a single volume.
When you run EACS, the system is just deleting the Data volume, then recreates it. The system then boots and contacts Apple to sign the volume.
FYI - As and aside, with Full Security turned on, the only application that can unlock and write the System volume is the macOS installer. So, what is happening during an O/S upgrade, is the installer unlocks the System volume, updates it, and then reboots the computer with the updated volume.
Example would be going from Sonoma to Sequoia. So does the process for the OS upgrade include a quick erase followed by the complete installation of the new OS once it unlocks that system partition or are just individual OS system files upgraded with no erase?