AMD's Ryzen CPUs have been out for almost a year, and it's now time for us to put out an easy to understand and easy to follow overclocking guide for the CPU. The AM4 platform has matured a lot, and so things are much more stable and overclocking is easier now than ever. AMD offers two ways to overclock their Ryzen CPUs; through the motherboard's UEFI and through AMD's Ryzen Master application.
We are going to focus on the UEFI as AMD has done an excellent job of covering how to overclock with their software. If you aren't okay with overclocking in the UEFI you can read AMD's Ryzen Master OC Guide.
The flow chart above is pretty basic but spells out some things you should know before you begin. At around 95C the CPU will throttle, so you want to stay at least 10-15C below that for safety. CPU core voltage maximum is 1.45v, and SoC voltage is 1.2v. AMD's Ryzen CPUs do not run off a VID table; they run between 0.2-1.5v depending on load and environmental characteristics, but when you overclock, you should not set anything above 1.5v (I doubt you could even cool a CPU at that voltage). You should expect a 3.9-4.1GHz overclock.
While temperature is typically your limiter, in this case, you will not be going over 4.1GHz on ambient cooling solutions. Some Thread Ripper CPUs can hit 4.2GHz, but Thread Ripper is made out of the top 5% of all Ryzen dies. I always aim for 4GHz, but I have seen some of my CPUs not hit 4.0GHz. The cool thing about the new processors is that their multipliers can be increased in 0.25 increments. AMD's AGESA code is the basic code AMD gives its partners to build a UEFI. AMD has made big leaps with code updates, especially on the memory overclocking side, and they publish a lot of information on their blogs as you can see here.