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Comment by phamilton | Hacker News Reader

A recurring theme is "build a processor that performs well on real workloads".

It occurs to me that AWS might have far more insight into "real workloads" than any CPU designer out there. Do they track things like L1 cache misses across all of EC2?

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Reality varies. Its a truism in optimization that the only valid benchmark is the task you are trying to accomplish. These chips have been optimized for an average of the tasks run on AWS (which is entirely sensible for them), but that doesn't mean they'll be the best for your specific job.

They'll definitely have information that traditional CPU designers won't. Check out this talk from Brendan Gregg (he's probably lurking), where he specifically calls this out:

https://www.brendangregg.com/blog/2021-07-05/computing-perfo...

See slide 26 (and the rest ofc :)).

Hard to track for other people’s VMs, but they probably have (or can sample) that data for every AWS-operated service (dynamo, S3, redshift, etc..)

There is a strong internal mandate for internal services to switch over to gravitron. So they either likely have this data, or are just trying to free up more x64 cores for external customers.

Yeah, this is key. They definitely optimize for their own services. And they don’t run S3 and redshift on the same cpu/server at the same time.

They may not run those particular services on the same hosts but they heavily use Lambda (and docker) which can share hosts and be tossed around the data centers to saturate cores.

AWS can also build slightly different CPUs under the same name for different workloads and not tell anybody.

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