AMD Ryzen 3000 "Zen 2" a Memory OC Beast, DDR4-5000 Possible
AMD's 3rd generation Ryzen (3000-series) processors will overcome a vast number of memory limitations faced by older Ryzen chips. With Zen 2, the company decided to separate the memory controller from the CPU cores into a separate chip, called "IO die". Our resident Ryzen memory guru Yuri "1usmus" Bubliy, author of DRAM Calculator for Ryzen, found technical info that confirms just how much progress AMD has been making.
This could turn into an additional selling point for AMD X570 chipset motherboards, as they'll have a memory frequency headroom advantage over boards based on older chipsets as their BIOS will include not just the increased memory clock limit, but also the divider mode. Of course this doesn't mean that you can just magically overclock any memory kit to these 5 GHz speeds - it's probable that only the best of the best modules will be able to get close to these speeds.
1usmus also discovered that the platform adds a SoC OC mode and VDDG voltage control. We've heard from several sources that AMD invested heavily in improving memory compatibility, especially in the wake of Samsung discontinuing its B-die DRAM chips.
https://www.techpowerup.com/255405/amd-ryzen-3000-zen-2-a-memory-oc-beast-ddr4-5000-possible