Over the past few weeks we have been able to tell you pretty much everything about AMD’s upcoming Ryzen processors. If you did not know the “X” on the end of some of the models refers to the availability of the XFR (extended frequency range) feature. XFR is sort of like a second stage boost that awards good CPU cooling with higher CPU clocks automatically. AMD models that have this feature include the Ryzen R7-1800X, R7-1700X, R5-1600X, R5-1400X, and R3-1200X.
So for example the R7-1800X has a base clock speed of 3.60 GHz and boosts up to 4.00 GHz. Its XFR range goes beyond 4.00 GHz. Now there are no set values for the XFR frequencies so we do not know how high they will go, this is likely because AMD does not want to advertise clock speeds that consumers cannot reach.