MacOS – OS X El Capitan different behaviours at start

macos

I have two MacBook Pro mid 2013, same hardware inside.
In the first one I had the following sequence of OSs.
Mountain Lion (factory) > Mavericks > Yosemite > El Capitan > El Capitan (Clean Install)

And whenever I start the Mac I have this flow
Apple Logo > User login (my user + guest user) > Loading (progress bar) > OS loaded

In the second MacBook I had
Mountain Lion (factory) > El Capitan

And this flow at start
Apple Logo > Loading (progress bar) > User login (my user + guest user) > OS "lazy" loaded ("lazy" = Status bar is loaded a few seconds after the screen with dock is presented)

Since there is a clearly difference in the behaviour of the two OSs, my question is: why does this happen? Is there a problem with one of the OSs? Which is the correct flow?

Best Answer

It might be that in the first case the boot partition is encrypted with FileVault. You then need to login to be able to read the boot partition.