Zen4 will feature a new overclocking technology dubbed as EXPO, short for Extended Profiles For Overclocking. This is similar to Intel’s XMP (Extreme Memory Profile). EXPO is said to be a major feature on AMD’s Ryzen 7000 CPUs, although not much light has been shed on the matter yet, officially. As per Wccftech’s sources, Zen4 will have DDR5-6000 memory as the sweet spot offering a 1:1 IFC Ratio. 1:1 Ratio : A 1 to 1 ratio essentially means that the memory (RAM) is operating at the same speed as the CPU memory controller, enabling for stable and maximum performance. 

Sweet Spot for Zen2 = DDR4–3800 RAMSweet Spot for Zen3 = DDR4–4000 RAMSweet Spot for Zen4 = DDR5–6000 RAM

DDR5-6000 is a really good speed allowing for major improvements in performance while being stable. You can surely use higher frequency RAM such as DDR5-6400. Although, all frequencies higher than the ‘sweet spot‘ will result in decrements in performance as the IFC ratio changes from 1:1 to 1:2. There’s an elephant in the room however. Zen4 does not support DDR4 RAM, so you are forced to purchase the newer and faster DDR5 RAM. Now, that’s not as bad as it sounds, but DDR5 RAM is some cases is 2x more expensive than DDR4. On the other hand, Intel plans to keep DDR4 support for Raptor Lake, slightly tipping the balance in favour of team blue.  Being a newer platforms that supports only DDR5 RAM, AMD will continue to revise their firmware for these chipsets. Do not expect a perfectly smooth start for Zen4. With everything new, newer problems arise. Despite being shackled in chains, Zen4 may outperform Raptor Lake efficiency wise. Raptor Lake even after massive improvements over Alder Lake fails to catch up to Zen3.

AMD Zen4 CPUs to Offer 1 1 IFC Sweet Spot at DDR5 6000 - 34