New Zen 5 128-core EPYC CPU wields 512MB of L3 cache

AMD is gearing up to launch one of the most cache-dense EPYC processors to date. HXL has discovered a new EPYC 9005 series Zen 5 part that boasts 512MB of L3 cache without using AMD's 3D V-Cache technology.

The EPYC 9755 sports 128 cores, 256 threads, and a peak turbo clock of 4.1GHz. The most interesting tidbit about this processor is that it boasts half a Gigabyte worth of L3 cache but doesn't have an "X" moniker at the end of its model name to denote that it comes with 3D V-Cache, similar to X3D models in AMD's Ryzen 7000 and Ryzen 5000 series.

If these new specs are not fabricated, it suggests that AMD will increase L3 cache sizes for its Zen 5- based EPYC processors. Compared to its predecessors, the EPYC 9755 has 33% more L3 cache than the 96-core EPYC 9654, which has 384MB of L3 cache spread across 12 CCDs. Compared to 3D V-Cache-enabled parts, the EPYC 9755 is just 128MB behind the 96-core EPYC 9684X , which features an additional slab of L3 cache installed above its 12 CCDs.

AMD is also purportedly increasing core counts for Zen 5 EPYC. With 128 cores and 256 threads, the EPYC 9755 has the same core count as AMD's EPYC 9754 Bergamo flagship, boasting 128 Zen 4c cores and 33% more cores than its more direct predecessor, the 96-core EPYC 9654.

This core count has several implications. It suggests that AMD is finally upgrading EPYC from 8-core CCDs to 16-core CCDs for its high-performance Zen cores. Bergamo had the same 16-core CCD configuration, but AMD could do this with Zen 4 by utilizing its more compact Zen 4c cores.

The higher core count means AMD can cram more cores into EPYC with fewer CCDs (or run more cores with the same amount of CCDs as Genoa). Assuming a 16 CCD configuration, the EPYC 9755 will only come with 8 CCDs, four fewer than the 96-core Genoa flagships.

Based on these simple specifications, Zen 5 EPYC looks very impressive. Not only is AMD boosting core counts, but it appears to be massively improving L3 cache density at the same time. With just 8 CCDs, AMD is cramming 64MB of cache into each individual CCD, which is twice the size of AMD's Ryzen 9000 and Ryzen 7000 L3 cache capacities.