What AMD does is not magic and is not beyond what others can do. My question is why they chose to have just 32MB for up to 80 cores when AMD can choose to have 32MB per 8-core chiplet.
As a comparison, an IBM z15 mainframe CPU has 10 cores and 256MB per socket.
> As a comparison, an IBM z15 mainframe CPU has 10 cores and 256MB per socket.
Well, that's eDRAM magic, isn't it? Most manufacturers are unable to make eDRAM on a CPU.
> My question is why they chose to have just 32MB for up to 80 cores when AMD can choose to have 32MB per 8-core chiplet.
From my understanding, those ARM chips are largely I/O devices: read from disk -> output to Ethernet.
In contrast, IBM's are known for database backends, which likely benefits from gross amounts of L3 cache. EPYC is general purpose: you might run a database on it, you might run I/O constrained apps on it. So kind of a middle ground.
Didn't Intel push eDRAM magic into various laptop chips around Broadwell?
> those ARM chips are largely I/O devices
Anything Neoverse-N1 is pretty good at general compute and databases. There's definitely a lot of Postgres running on AWS Graviton2 instances already :)
As a comparison, an IBM z15 mainframe CPU has 10 cores and 256MB per socket.