AMD Zen 4 Architecture Explained: What Is Zen 4 Genoa And Zen 4C Bergamo?

AMD has officially announced the Instinct MI200 server accelerators along with EPYC Milan-X processor with 3D V-cache technology. At the same event, the company also gave a sneak peek at the upcoming Zen 4 architecture, which will power the future EPYC processors using TSMC 5nm fabrication, the first AMD processor to do so.

During the AMD data center event, AMD announced two server CPU models -- Genoa, which uses Zen 4 type cores, and Bergamo, which uses Zen 4c type cores. Both variants will offer more performance with more cores, and improved power efficiency.

AMD Genoa Zen 4 EPYC CPUs

The AMD Genoa will be based on the Zen 4 architecture. These CPUs will offer up to 96 cores, which is higher than that of the current generation EPYC Milan and Milan-X. EPYC Genoa CPUs will hit the market by late 2022 or by early 2023 with support for features like PCIe Gen 5 and DDR5.

AMD Bergamo Zen 4c EPYC CPUs

The AMD Bergamo will also be based on the same Zen 4 microarchitecture and will offer up to 128 cores. However, unlike the Genoa, the Bergamo will be optimized for cloud computing, hence the letter "C" in the Zen 4c. The Zen 4c cores are expected to be physically smaller than the Zen 4 cores, which will be designed for thread density.

AMD has also confirmed that both Genoa and Bergamo will use the same socket, which further confirms that the Bergamo has small-sized cores. The Genoa and Bergamo will offer twice denser, twice power-efficient, and 1.25 times more silicon performance when compared to CPUs based on 7nm fabrication.

Can We Expect A Hybrid AMD CPU?

From what we can understand, the two new microarchitectures from AMD look similar to e-cores and p-cores on the Intel Alder Lake CPUs. However, AMD has not revealed anything about CPUs using both microarchitectures. However, the company might do the same in the coming days, especially for the consumer products to increase energy efficiency.

Milan and the Milan-X EPYC CPUs will be the last set of server-grade processors to be manufactured using 7nm fabrication, and the upcoming Genoa and Bergamo will be fabbed using TSMC's N5. We also expect the company to use 5nm fabrication for the upcoming consumer-grade processors.