YouTuber and leaker Moore’s Law is Dead revealed new information regarding AMD’s future architecture plans. According to leaks, AMD is working on a “dense” version of Zen 4 called Zen 4D. Zen 4D is basically a fork of Zen 4 that strips out features and reduces clock speeds.
It will also feature a newly designed cache system. All of this is to slightly reduce single-core performance in exchange for greatly increased multi-core performance. This would also allow AMD to increase the chip density, hence the “D” in the name.
If the leaks are true, it seems the company may be creating its own hybrid architecture to compete with the success of Intel’s 12th-gen Alder Lake chips. This follows in the footsteps of both Intel and Apple, who have utilized similar architectures in their respective CPU designs.
These Zen 4D processors would have about half the L3 cache of regular Zen 4 and feature 16 cores per chiplet. Moore’s Law is Dead stated that Zen 4D is expected to have simultaneous multithreading (SMT), but they couldn’t be 100% certain. He was also uncertain if Zen 4D would support AVX-512 but did confirm that Bergamo, AMD’s 128-core server-grade EPYC CPU slated for second quarter 2023, would feature the new architecture.
The new architecture for Zen 5 was also leaked, and this is by far the most interesting news. The leaks suggest that Zen 5 will be AMD’s first hybrid processor architecture. It would use eight Zen 5 “big” cores and up to 16 Zen 4D “little” cores. Zen 5 is also rumored to be codenamed Granite Ridge and based on the Ryzen 8000 series processors built on TSMC’s ridiculously tiny 3nm process.
As we’ve seen with Intel’s Alder Lake chips and Apple’s M1 Pro/Max CPUs, the hybrid approach can offer huge performance increases. It makes sense that AMD would architecture their chips in a similar manner, as Zen 5 could offer a 20-25% IPC increase over Zen 4. The problem is that Zen 5 is still a few years out, and Alder Lake currently outperforms AMD’s best consumer chips.