Processes performed during MacOS installation I wonder on what so much time is spent during installation or upgrade to new MacOS. In other words: having strongest machine (MacbookPro) with fastest hard drive (1GB/s read/write abilities) and having fast internet connection (30Mbps) - why update between two consequent minor version (i.e. from 10.12.2 to 10.12.3) takes 30 minutes - even if update declared to be 800 MB in size. I expect in answers mentioning specific functional actions, if someone knows or can guess ones.
(If you can add anything to this list, it would be greatly appreciated.)


Firmware updates
Each and every macOS installer includes a firmware update package that has to run before the "regular" install process can be begun.