The rumor comes in this case from Inpact Hardware who reportedly received information from AMD sources claiming that they are planning an HBM variant of their upcoming Zen 4 core architecture EPYC Genoa server CPUs. While we have learned a lot about CPUs Genoa ‘standard’, this would be the first time we’ve heard of integrating an HBM memory variant into the equation.
Zen 4 architecture meets HBM memory
According to the information published in their report, a Zen 4 architecture EPYC CPU with HBM memory is a recurring question among AMD partners. Intel has already announced its HBM variant of Sapphire Rapids, although these chips are not expected to be available in mass until 2023. AMD is reportedly preparing its Milan-X lineup as a middle ground between Zen 3 and Zen 4, which would host 3D chip stacking technology although it is not yet clear whether this is going to be based on CCD or V-Cache (similar to the next-gen Ryzen Zen 3).
AMD is likely to be able to offer Milan-X chips with 3D V-Cache as a demonstration of how low-level cache can help improve performance on bandwidth-bound workloads and ultimately scale it up with more. Premium options using HBM memory when EPYC Genoa is on the market. The difference between Milan and Milan-X in terms of release is around 2-3 quarters and the same period of time can be expected until we see a line of AMD EPYC Zen 4 CPUs with HBM memory.
What will definitely be interesting to see will be the implementation of AMD’s HBM memory, as they can either use traditional methods with the chips outside the matrix or they could use next-gen 3D chip stacking technology. Intel has not confirmed which solution they will use in this regard for their own HBM memory integration, but they most likely use EMIB and Foveros packaging and interconnect technologies to integrate HBM memory into their Xeon CPUs.
AMD EPYC Processor Families
|Family name||AMD EPYC Naples||AMD EPYC Rome||AMD EPYC Milan||AMD EPYC Genoa|
|Name||EPYC 7001||EPYC 7002||EPYC 7003||EPYC 7004?|
|Architecture||Zen 1||Zen 2||Zen 3||Zen 4|
|Lithography||14nm GloFo||7nm TSMC||7nm TSMC||5nm TSMC|
|Socket||LGA 4094||LGA 4094||LGA 4094||LGA 6096|
|Maximum number of cores||32||64||64||96|
|Maximum number of threads||64||128||128||192|
|Maximum L3 cache||64 MB||256 MB||256 MB||384 MB?|
|Chiplet design||4 CCD’s (2 CCX’s per CCD)||8 CCD’s (2 CCX’s per CCD) + 1 IOD||8 CCD’s (1 CCX per CCD) + 1 IOD||12 CCD’s (1 CCX per CCD) + 1 IOD|
|Memory channels||8 Channel||8 Channel||8 Channel||12 Channel|
|PCIe||64 Gen 3||128 Gen 4||128 Gen 4||128 Gen 5|
|TDP range||200W||280W||280W||320W (cTDP 400W)|
As we can see, AMD’s plans for its EPYC CPUs are not only broad but also ambitious. The next generation, EPYC Genoa coming in 2022, will integrate all the technology that AMD has been working on for years, including a new socket, TSMC 5nm lithography, support for DDR5 RAM and even PCIe 5.0. If they now create a “Premium” category of these processors with HBM memory, they may be able to stand up to it and even leave Intel and its Xeon Sapphire Rapids CPUs in the lurch.
We cannot forget, on the other hand, that processor manufacturers tend to first integrate the latest technologies into their professional platforms, but that they almost always reach the domestic ecosystem later. So we can’t help but think that it is potentially possible that we will see a next generation AMD Ryzen CPU with HBM memory, so there is the data. Let’s not forget, on the other hand, that we are simply handling rumors and all this information might not come true in the end.