Zen 5 Is Coming But Zen 6 Is Rumored To Pack Up To 256 Cores And 512 Threads
We're fast approaching Computex Taipei 2024, where AMD is broadly expected to announce its next-generation processors based on the Zen 5 architecture. However, the combined efforts of leaker Everest and veteran programmer InstLatX64 may have revealed some fascinating details about the company's next-next CPUs, based on its Zen 6 architecture.
First up, the concrete information. Everest made a table listing all of the known models of AMD's EPYC Turin processors. These will be the next-generation EPYC 9005 series server processors based on Zen 5. The fastest of the known models sports sixteen CCDs (core chiplet dice), giving it a whopping 128 cores, but there's also a high-density chip with twelve 16-core CCDs for a massive 192 cores in a single socket. We don't know much about Zen 5c yet, but the 500W TDP that Everest marks down for that part is rather telling.
That information is all confirmed, as it's all regarding real hardware that people have in hand for testing. However, in his chart (below) that shows the top-end configuration of each EPYC generation, InstLatX64 also compiled current leaks and rumors about Zen 6. Your eyes do not deceive you: that says 1024 threads in a two-socket configuration. That means each processor will have 256 cores with simultaneous multi-threading spread across 8 thirty-two-core CCDs.
Chart compiled by InstLatX64 (@InstLatX64 on Xwitter)
CCDs are chiplets, but CCX stands for "Core CompleX", and it's the fundamental building block of a Ryzen processor. Early Ryzen chips had their eight cores split into two four-core CCXes, but starting with Zen 3, all eight cores were unified into a single CCX. This results in improved multi-core performance. However, Zen 4c cores, like those found in Bergamo, are organized into pairs of 8-core CCXes sharing a CCD. It appears that in the Zen 5c and Zen 6 parts, all of the cores are consolidated into a single CCX once more, which is nice.
Another known insider, Kepler (@Kepler_L2 on Xwitter), remarked in reply to InstLatX64 that Zen 6 will actually have three separate CCD designs: one with eight cores, one with 16 cores, and one with 32 cores. We can presume that Ryzen chips will feature the 8-core dice, while EPYC parts will likely feature the 16- and 32-core chiplets more prominently—although if we see an EPYC 4006 series, maybe there will be EPYC parts with 8-core CCDs, too.
