AMD's new Ryzen 7000 series "Zen 4" CPUs usher in the world of DDR5 memory, with the company making it clear that DDR5-6000 memory is the "sweet spot" for your new Zen 4 system.

On the official AMD Discord server, Technical Marketing Manager Robert Hallock confirmed the news himself: using the AUTO setting will usually give you the most performant result unless you have an "astonishing overclocker". Hallock was fielding questions on Discord from users, in regards to DDR5 memory and their new Ryzen 7000 series "Zen 4" CPUs.
Hallock says that at its native setting, DDR5-5200 will operate in a 2:1:1 mode or 1733:2600:2600 clock, to which someone else replied saying "what is the sweet spot? 6000mhz" to which Hallock replied "roughly, yes" and then he said that to be more specific the "sweet spot" he's referring to is the best compromise of cost/stability + performance + availability + ease.
AMD's new EXPO DDR5 memory overclocking technology will include native DDR5-5200 memory support, driving up to support DDR5-6400 memory: but as this news points out, DDR5-6000 memory is the "sweet spot" according to AMD. DDR5-6000 memory kits will be found with EXPO technology support, where they'll offer the best performance with the lowest latency in 1:1 FCLK mode.

Hallock explained on Discord: "The reason why we say "AUTO:1:1" is now ideal because the FCLK will automatically change depending on what memory speed is in the DIMM slots. There's no "one size fits all" ideal fabric frequency. For example: JEDEC 5300 fclk goes to 1767, 6000 RAM should go to 2000 fclk. Each memory speed has its own optimal fclk, which is why I'm gently guiding people to not worry about what the fclk is because it's going to change with RAM speed and the AUTO setting will usually give the most performant result unless you have an astonishing overclocker".
"And "get the highest possible fclk" is no longer the rule like it was on AM4. In short".