Every time you turn on or reboot your Macbook, the percentage is heavily loaded by what processes?

Question

macOS

I use MacMini and MBA with El Capitan and Siera respectively.
The phenomenon is observed in both cases on both versions of the OS.
With a fresh start or reboot, Air goes into a complete "swap", mini just runs a little and at the same time a wild 80-100% load of the processor starts in the background. This can be seen from the iStat Menu and the actual temperature readings, as well as the growing noise of the coolers.
System Monitors - pure...uh.
What kind of demons? ;)
Accordingly, it lasts for 20-40 seconds, then everything subsides to zero and then as if nothing had happened.
When you enter from sleep mode, this is not observed.
sinned on Yandex Disk. this process is accompanied by data synchronization from the server, but turning it off - all the same, the load does not go anywhere. It's not about him.

Answer 1

karoch, ... the main zapara - Spotlight and indexing. Cool thing, smart, but I use it once every thousand years, until I cut it off and put privacy on the folders.
I wonder how Alfred works?
solution ..
proyabloko.com/sekrety/chto-za-ptica-zaletela-v-ma...
iCloud also loads like yandexDisk when synchronizing data.
like everything. If you turn it off, only a very small load of a few seconds will remain at the start of the applications.

Answer 2

Look at how much everything turns on with the system
. Something of this apparently eats when you turn it on, which MB data it collects at a pace.