How long does a factory reset take on a Samsung Galaxy S3?

[AC Question]

In trying to figure out if anyone had asked this question, I came across quite a few horror stories about seemingly innocent factory resets gone completely wrong. So, how long should I expect this to take before there's a problem?

And if there is a problem, what can I do to fix it?

 

[srkmagnus]

The factory reset portion may take a few minutes. The first reboot will take 5-10 minutes. Let us know if you have any questions.

 

[Jimmy Walker2]

Help !!!!!!!! Factory reset and it will mot boot back up Stays at the main screen with T Mobile 4G LTE screen What can I do