AMD’s next-generation EPYC Milan CPUs are closing in and we’ve seen the power of the Red Team’s Zen 3 server for the first time. The EPYC Milan server processors will be part of the third-generation EPYC line, replacing the EPYC Rome line that launched almost two years ago, while offering significant improvements in HPC and data center applications.
AMD 3rd Gen EPYC Milan CPU Spotted, 7nm + Zen 3 Powered Early ES Chip with clocks up to 2.2 GHz
The AMD EPYC Milan CPU family will be powered by new Zen 3 cores that will be based on the TSMC 7nm + process node. While we’ve learned a lot from the leaks and rumors above, the CPUs themselves haven’t been featured anywhere until now.
The latest bits and info come from ExecutableFix on Twitter, which managed to get details on an unpublished AMD engineering sample. The CPU was mentioned in a changelog for the Linux operating system and has the “AMD Eng Sample: 100-000000114-07_22 / 15_N” code name. The code name gives us a very early look at the ES clock speeds that are set on a 1.5 GHz basis and a 2.2 GHz boost. The core count for this specific chip is not yet mentioned. The following is the main log file for the EPYC Milan CPU:
Click this issue on Milan rhel8.3.0-av hosts when hot plugging vcpu to rhel8.3.0 guest:
[root@amd-milan-03 home]# / usr / libexec / qemu-kvm -cpu EPYC -device EPYC-x86_64-cpu, socket-id = 1, core-id = 0, thread-id = 1, id = cpu1 -m 4096 -smp 1, threads = 2, cores = 1, plugs = 3, maxcpus = 6
qemu-kvm: -device EPYC-x86_64-cpu, socket-id = 1, core-id = 0, thread-id = 1, id = cpu1: Invalid CPU [socket: 22009, die: 0, core: 0, thread: 1] with APIC ID 44019, valid index range 0: 5host version information:
kernel-4.18.0-202.el8.x86_64 & qemu-kvm-5.0.0-0.module + el8.3.0 + 6620 + 5d5e1420.x86_64Host CPU information:
model name: AMD Eng Sample: 100-000000114-07_22 / 15_N
The filter reports that EPYC Rome also featured similar clock speeds in the early ES state, the final variants of which boost clocks up to 3.4 GHz. Interestingly, Komachi refers to the AMD EPYC Milan chip as Genesis, which is the name in Key to the AMD Ryzen Threadripper 4000 series line (Genesis Peak) that will feature Zen 3 cores. Considering that the AMD EPYC and Threadripper CPUs have a lot in common, we can see why Genesis is referenced here.
That said, I personally don’t expect to see a next-generation Threadripper line until mid-2021, as AMD has yet to unveil its Ryzen 4000 ‘Vermeer’ desktop line based on the core Zen 3 architecture.
AMD CPU Roadmap (2018-2020)
| Ryzen family | Ryzen 1000 Series | Ryzen 2000 Series | Ryzen 3000 Series | Ryzen 4000 Series | Ryzen 5000 Series |
|---|---|---|---|---|---|
| Architecture | Zen (1) | Zen (1) / Zen + | Zen (2) / Zen + | Zen (3) / Zen 2 | Zen (4) / Zen 3 |
| Process node | 14nm | 14nm / 12nm | 7nm | 7nm + / 7nm | 5nm / 7nm |
| High-end server (SP3) | EPYC ‘Naples’ | EPYC ‘Naples’ | EPYC ‘Roma’ | EPYC ‘Milan’ | EPYC ‘Genoa’ |
| Maximum number of cores / threads on the server | 32/64 | 32/64 | 64/128 | TBD | TBD |
| High-end desktop (TR4) | Ryzen Threadripper 1000 Series (White Haven) | Ryzen Threadripper 2000 Series (Coflax) | Ryzen Threadripper 3000 Series (Castle Peak) | Ryzen Threadripper 4000 Series (Genesis Peak) | Ryzen Threadripper 5000 Series |
| Max HEDT cores / threads | 16/32 | 32/64 | 64/128 | 64/128? | TBD |
| Conventional desktop (AM4) | Ryzen 1000 Series (Summit Ridge) | Ryzen 2000 series (Pinnacle Ridge) | Ryzen 3000 Series (Matisse) | Ryzen 4000 Series (Vermeer) | Ryzen 5000 Series (Warhol) |
| Max core / core threads | 8/16 | 8/16 | 16/32 | TBD | TBD |
| APU Budget (AM4) | N / A | Ryzen 2000 Series (Raven Ridge) | Ryzen 3000 Series (Picasso Zen +) | Ryzen 4000 Series (Renoir Zen 2) | Ryzen 5000 series (Cezanne Zen 3) |
| Year | 2017 | 2018 | 2019 | 2020/2021 | 2021/2022? |
AMD EPYC Milan: 7nm Zen 3 cores, SP3 socket compatible, PCIe 4.0, DDR4 memory
AMD EPYC Milan processors would succeed the current line of EPYC Rome. The fundamental change for the EPYC Milan line would be the new Zen 3 core architecture that will be based on an advanced 7nm process node. From what we know and what AMD has officially shown, AMD Zen 3-based EPYC Milan processors would primarily focus on overall performance enhancements per watt, but that doesn’t mean we aren’t looking for major updates.
So far, AMD has confirmed to itself that Zen 3 brings a new CPU architecture, which helps to get significant IPC gains, faster clocks, and even more cores than ever before. Some rumors have even pointed to a 17% increase in IPC and a 50% increase in Zen 3 floating point operations along with a major cache redesign.
When asked what kind of performance the Milan CPU core microarchitecture, known as Zen 3, would gain, it will offer relative to the Zen 2 microarchitecture Rome is based on in terms of instructions processed per clock cycle of CPU (IPC), Norrod noted that: Unlike Zen 2, which was more of an evolution of the Zen microarchitecture that powers first-generation Epyc CPUs, Zen 3 will build on a whole new architecture.
Norrod qualified his comments by noting that Zen 2 delivered a higher IPC gain than normal for an evolutionary update: AMD has said that it is approximately 15% on average as it implemented some ideas that AMD originally had for Zen, but had to leave on the cutting board. However, he also claimed that Zen 3 will offer performance gains “in line with what you would expect from a completely new architecture.”
– The street
In a recent slide, AMD showed its Zen 3-based 7nm processors that offer better performance per watt than Intel’s 10nm Ice Lake-SP Xeon chips. As for the new features, in addition to presenting its central Zen 3 design, Milan would offer socket compatibility with SP3 platforms, offer support for DDR4 memory, PCIe 4.0 interface, and is said to offer 64 cores and 2x threads (128 threads) .
The chips will have a TDP of 120-225W, which is similar to existing parts in Rome. Summing up everything for EPYC Milan, we are analyzing the following main characteristics:
- Advanced Zen 7nm 3 cores (~ 64 cores / 128 threads)
- Pin compatible with socket SP3
- 120W-225W TDP SKU
- PCIe 4.0 support
- DDR4 memory support
- Launching in 2020
Another interesting detail for the central design was shared during the presentation. AMD has shown that, unlike Zen 2, which has 16MB of L3 cache per CCX within a CCD, Zen 3 would present a shared cache (32MB +) for each die. This would allow all cores to share all of the available L3 cache memory in the die instead of each CCX having its smallest and separate cache shared between cores. This may also be a potential confirmation that Milan offers 8 Zen 3 cores within a single CCX.
Going forward when it comes to release date, AMD has reaffirmed that EPYC Milan CPUs will ship in late 2020. CPUs will go head to head with Intel Cooper Lake-SP 14nm and Ice Lake-SP CPUs. 10nm that will be available this year.
