A while back, rumors started to surface that AMD might be repurposing its Zen 4 processors for the existing AM4 socket to meet the needs of the budget PC audience. However, unsurprisingly, this appears to have been a hoax. According to ProHardver, board partners have no information about these chips, and Zen 4 will almost certainly be limited to the new AM5 socket.
There is a design limitation preventing AMD from bringing (even if it wanted to) Zen 4 to existing B450/B550/X570 AM4 motherboards. The The AM5 socket has been designed to be compatible with existing AM4 coolers which may not seem like a big deal, but it actually is. The 5nm Zen 4 chips are designed so that their height allows the IHS to be compatible with older heatsinks and AIO coolers.
The Zen 4 chiplet will not fit optimally into the AM4 case, and manufacturing it would require redesigning the chipset itself to make its height suitable for the older socket. On the bright side, the outlet claims there is a double chiplet Zen 3 part based on V-Cache 3D with a whopping 128MB of stacked L3 cache (200MB in total) which may launch later this year.
It’s hard to tell if this is just a prototype or a commercial design, but AMD is investing heavily in 3D Stacked V-Cache. The Ryzen 7 5800X3D which launched almost 2 years after the mainstream Zen 3 family, manages to deliver generational gains in gaming workloads, beating the Intel Core i9-12900K inch for inch.
Many rumors already speak of Zen 4 chip leveraging 3D V-Cache with targeted Q4 2022 launch windowso it won’t be surprising if AMD manages to sneak in another AM4 flagship with twice the cache of the Ryzen 7 5800X3D.