AMD Genoa Takes Epyc to 96 Cores

AMD’s fourth-generation Epyc takes server processors to a new level, delivering 50% gains in core count, memory bandwidth, and I/O speed relative to the previous generation.

Linley Gwennap

AMD’s fourth-generation Epyc takes server processors to a new level, delivering 50% gains in core count, memory bandwidth, and I/O speed relative to the previous generation, which is already the industry’s most powerful. When comparing the highest-end models, the new design (code-named Genoa) more than doubles the performance per socket of Intel’s current Ice Lake-SP. Even the upcoming Sapphire Rapids will do little to close this gap.

Genoa features the same Zen 4 CPU as AMD’s recent Ryzen 7000 PC processors. A shrink to 5nm fits up to a dozen compute chiplets per package, for a total of 96 CPU cores and 384MB of cache—far beyond any current server processor. The new larger package con¬nects to 12 DDR5 DRAM channels, more than doubling memory bandwidth from the third-generation Epyc, code-named Milan. Genoa supports the newest I/O standards such as PCIe Gen5 and CXL. According to posted SPECrate scores, performance doubles that of the best Milan.

AMD introduced a full range of Epyc products based on Genoa, from the flagship Epyc 9654 to the low-end Epyc 9124. They range up to 400W in power and $11,805 in list price. Already in production, the new processors upgrade the third-generation Epycs that debuted two years ago. Milan relies on the older Zen 3 CPU and is limited to 64 cores. Establishing a performance lead over Xeon, Milan has helped AMD gain share in server processors.

Intel’s current Xeon Scalable products, including the top-of-the-line Xeon 8380, are based on the Ice Lake-SP design, which scales to 40 CPU cores. The company says its new Sapphire Rapids design is in production, but it has withheld product specifics. That design reportedly scales to 56 cores while improving per-core performance, but it still falls well behind Genoa in both regards.