https://wccftech.com/amd-ryzen-3000-cpus-zen-2-7nm-up-to-5000-mhz-ddr4-memory-support/

AMD will be officially announcing their 3rd Generation Ryzen processors in a few weeks and it seems like there will be a major upgrade to the memory controller which would allow for faster memory support, theoretically.

The information comes from the author of the DRAM Calculator for Ryzen processors 1usmus or Yuri Bubliy. He has mentioned on his Twitter feed that the maximum value of the frequency of the AMD Zen 2 generation of processors or Ryzen 3000 series is 5000 MHz and the UCLK is half of that so it should be set at 1250 MHz effective. The difference between the memory clock and UCLK is that the memory clock is specific only to the internal and external memory clock while the UMC clock is specific to the unified memory controller. Following is a set of clock domains for Zen based Ryzen CPUs (via WikiChip):