Alleged AMD EPYC 7773X Milan-X CPU Specs Leak With 64 Cores And A Massive 768MB Cache

It has been several months since AMD rolled out its 3rd Gen EPYC 7003 series (Milan) of big iron server chips based on its Zen 3 CPU architecture, with up to 64 cores and 128 threads to hammer data center workloads. Then came rumors of a "Milan-X" refresh featuring stacked 3D V-cache. Well, as a launch presumably nears, some leaked specifications have found their way to the web.

Since those rumors first came to be, AMD subsequently confirmed plans to incorporate stacked 3D V-cache on its future CPUs, starting on the consumer side with a refreshed Ryzen 5000 lineup. This is something AMD has been collaborating on with its manufacturing partner, TSMC, and the company is pitching it as the most advanced and flexible active-on-active stacking technology in the world.

Nothing has been officially confirmed on the server side, but it makes sense that AMD would inject 3D V-cache onto its data center chips. AMD's upcoming Milan-X parts would essentially pair a Genesis I/O die with stacked chiplets to offer significantly more L3 cache. How much more? If the latest leaks are accurate, Milan-X CPUs would top out at a whopping 768MB of L3 cache, up from a ma of 256MB currently.

EPYC 7773X Tweet

According to ExecutableFix, a popular tech leaker, the top offering in the refreshed lineup will be the EPYC 7773X with 64 cores and 128 threads clocked at 2.2GHz (base) to 3.5GHz (max boost), with 768MB of L3 cache courtesy of the 3D V-cache injection. It would also have a 280W TDP.

As a point of comparison, the existing EPYC 7763 is also a 64-core/128-thread part clocked at 2.45GHz to 3.5GHz, with 256MB of L3 cache and the same max 280W TDP. So the new part will have a slightly lower boost clock, but the same boost clock and a whole lot more L3 cache.

The same leaker also posted specs for a few other Milan-X CPUs. Here's a rundown (along with the one above)...
  • EPYC 7773X: 64 cores / 128 threads, 2.2GHz to 3.5GHz, 768MB L3 cache, 280W TDP
  • EPYC 7573X: 32 cores / 64 threads, 2.8GHz to 3.6GHz, 768MB L3 cache, 280W TDP
  • EPYC 7473X: 24 cores / 48 threads, 2.8GHz to 3.7GHz, 768MB L3 cache, 240W TDP
  • EPYC 7373X: 16 cores / 32 threads, 3.05GHz to 3.8GHz, 768MB L3 cache, 240W TDP
In each case, we're looking at the Core Complex Dies (CCDs) each wielding 32MB of cache (8x32MB) for 256MB total, which is the configuration the EPYC 7003 series maxes out at, plus another 64MB of 3D V-cache (8x64MB) for a total of 512MB of additional cache. That brings the grand total to 768MB of total L3 cache.

These will undoubtedly cost more than their regular Milan counterparts, but how much more remains to be seen. Depending on where pricing lands, Milan-X could end up a very popular option.