More cores, lower consumption and more attractive costs: With the Epyc 97X4 “Bergamo”, AMD is launching new CPUs based on a variant of the Zen 4 architecture that have to compete with ARM-based server processors.

AMD is launching a new line within its fourth generation of Epyc processors. The AMD Epyc 97X4 chips – Bergamo for friends – are specially developed for cloud native computing. In other words, they offer many inexpensive cores. Because more cores that consume less power allow cloud providers to collect more containers on a server.

“Cloud-native workloads like containers and microservices have different requirements than general computing workloads,” said AMD CEO Lisa Su. “Throughput and density are more important than maximum performance.” Bergamo was built for this.

X86 vs ARM

AMD didn’t invent hot water here. Rather, Bergamo is a response to a threat in the market. This time it comes not (only) from Intel, but from ARM. Finally, the ARM architecture proved to be extremely suitable for cloud-native applications. Just ask AWS customers, who are increasingly reaping the value of the cloud provider’s ARM-based Graviton processors.

Graviton (and other ARM competitors) offer many low-cost cores, which isn’t traditionally a specialty of the x86 architecture. ARM wants to change that with Bergamo. In order to be able to compete with ARM, the chips were developed on the basis of the Zen 4c architecture. This is a variant of Zen 4 that focuses on efficiency.

Bergamo vs Genoa

“Bergamo has the same 6nm I/O chiplet as Genoa,” says Su. “Actually, the entire chip is the same except for the CCD (core chiplet matrix).” It contains the Zen 4c cores. Despite the higher efficiency, Zen 4c is not fundamentally different from the Zen 4 cores in Genoa, Su clarifies. “We took the same core design as Genoa, but optimized it for density and performance per watt rather than raw performance.” This was done primarily by rethinking the physical implementation of the cores and restructuring the cache hierarchy with a focus on throughput.

“Bergamo is a good example of our modular design,” Su continues. Since the Genoa CPUs and the Bergamo CPUs are identical except for the CCD component, they are compatible in terms of both software and platform. “Customers can choose whether they prefer Epyc 4 Genoa or Bergamo in one server.”

128 cores and more efficiency

The result is a new division within fourth-generation Epyc chips, with the most robust component in the Bergamo family packing up to 128 Zen 4c cores into a single chip. AMD claims that Zen 4c is up to 2.7x more efficient and supports up to 3x more containers per server than a non-ARM, but Intel Xeon Platinum 8490H server.

In any case, Bergamo is an important building block for AMD, which is fully focused on cloud-native servers. “AMD Epyc Bergamo is actually our first CPU designed specifically for such workloads,” says Su. Although AMD presents Intel as a competitor, both parties are actually pulling the same boat here. Finally, AMD’s Bergamo chips aim to show that x86 has a future in a world where ARM’s Neoverse designs are gaining traction.

AMD Epyc 4 Bergamo is currently being phased out in bulk and shipments to AMD’s hyperscaler customers.