AMD EPYC 7003 Updating the EPYC 7002
Next, we wanted to talk about what is being updated, specifically the architecture. This is a much less dramatic shift than we saw from the EPYC 7001 to EPYC 7002, but it still can have a big impact on performance.
AMD EPYC 7003 Zen 3 Update
AMD calls its microarchitecture Zen followed by a generation. This is Zen 3 and AMD says it is worth around a 19% higher IPC.
Many of these slides are going to look familiar. AMD Zen 3 and AMD Ryzen 5000 series have been out for some time and AMD leverages the microarchitecture across product lines.
Here is a summary of major changes compared to Zen 2. For our purposes in the server space, Zen 2 is the AMD EPYC 7002 series codenamed “Rome” and Zen 3 is EPYC 7003 “Milan”. Sometimes when using these terms all day we make the incorrect assumption that everyone knows this translation.
AMD has new front end that helps fill its caches. A big part of AMD’s architecture is leveraging massive on-chip caches to ensure that its execution units are not stalled waiting for data.
As we are seeing as a broader industry trend, we are getting wider execution engines.
This extends to integer execution.
Typically integer operations are important in data center/ enterprise workloads making these improvements especially helpful.
On the floating point side, we get another set of improvements. We are going to let you browse the slides if interested.
On the load/ store side, AMD again is making advancements. The key here is that AMD is tweaking its architecture with each generation. We are not getting 3-7% improvements. The large numbers of improvements mean we are getting much more than recent historical norms.
The load/ store engine is designed to keep data flowing through the execution units. This is a common processor theme. We even see AI chips focusing on this. Now that we are in an era of increasing core or execution unit counts, there is more pressure on the structures to deliver the correct data to keep those execution units doing useful work.
AMD also has some ISA enhancements. We are not going into these too deeply, feel free to read these if interested.
This is focused on the Zen 3 core, but an EPYC 7003 processor is much more than a core. Next, we are going to look at how AMD takes its Zen 3 core IP and creates the Milan processor.