When on login I click on the user, immediately shows password field but before I can type it I have to wait some seconds, sometimes even 5! I don't see this problem on other computers that I have, only one has this behavior. Anyone has this problem too? How can I check which components slowdown login time?
SnapOverflow
It could just be your processor(s) warming up, same with the video card. I sometimes have a similar problem, however, you can still type while it doesn't show the password being entered, you can even press enter. It'll still take a few seconds for the computer to realize that you've told it to login.
Out of curiosity, is this only after shutdown, or sleep and hibernation too?
One reason could be a very low video performance (there are some video effects from writing the user name to writing the password). Is your video performance good ?
My computer does the same thing. It's probably just finishing some things in the background so that it can show you a login screen more quickly. Some initial keyboard lag is usually likely when resuming from hibernation or starting up for the first time.