AMD recently announced that 7Nm's Zen 2 processor and MI 25 (Vega Refesh) have been designed and completed, and the former expects the end of the sample.

According to the official saying, Zen 2 will be a multi-dimensional improvement to the Zen architecture; 7nm+'s Zen 3 is also advancing in an orderly way, and is expected to meet with you in 2020. Zen's chief architect, Mike Clark, was the first official announcement of Zen 5 in April, and the outside world is expected to be built on GF's 3nm technology.

WCCFTech produced a possible product layout for Zen 2/Zen 3 based on message burst, in which Zen 2 will start from 12 cores, the highest 16 core, and the product name Ryzen 3000 series, then the suitable motherboard will be the 500.
Zen 3 continues to deduce, Ryzen 4000, the core configuration is similar to Zen 2.
As the information is still in the early stage and for reference, we expect that AMD can start more information on Zen 2 at the Taipei computer exhibition in June.
