to my knowledge, hitting with 4GHz with a 1600X isn't guaranteed but it's not that rare. you certainly got a good chip, but it's not a one-in-a-million
Does not matter you won or not, you got a good chip! 4 GHz with 6 cores was i7 6800K levels back then in the dark ages.
Have a shot at 4.1 or 4.2 GHz (see my 1800X in sig @4.2 GHz, 1.45V) Good luck!
Hmm. I wonder if my chip could do that with lower voltage? Right now it's running at 3.9Ghz at 1.288 volts witch i think it's a pretty low voltage . Either way, you have a good chip. May the force be with us.