Famed overclocker 'der8auer' has managed to overclock the new AMD Ryzen 7 2700X to cross the 6 GHz on all cores. He managed to achieve this by first selecting the best CPUs for the task and then subjecting them to LN2 cooling. Consumer use isn't anywhere going to get close to that figure but it is still good to know that Ryzen are really as overclocker-friendly as AMD claims.
https://www.notebookcheck.net/The-AMD-Ryzen-7-2700X-gets-overclocked-to-a-whopping-6-GHz-on-LN2.300094.0.html