
Amazon's homegrown Graviton processor was very nearly an AMD Arm CPU - rbanffy
https://www.theregister.co.uk/2018/11/27/amazon_aws_graviton_specs/
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ac29
Key takeaway: "The con: it's too damn slow. It does well on the Phoronix Test
Suite. It does poorly benchmarking our website fully deployed on it (nginx +
php + MediaWiki and everything else involved). This is your "real world" test.
All 16 cores can't match even 5 cores of our Xeon E5-2697 v4" [0].

Granted, x86 has seen far more optimization work than ARM, but its unfortunate
(but not unsurprising) they can't even come up with 1/3 of the speed of a 2016
Xeon. Amazon will need to rethink pricing, if they don't want this to get
pigeonholed into running ARM-specific tasks only.

[0]
[https://twitter.com/david_schor/status/1067456537264832512](https://twitter.com/david_schor/status/1067456537264832512)

~~~
gchadwick
> they can't even come up with 1/3 of the speed of a 2016 Xeon

Ultimately it's the total cost to run your application that's important, not
the raw speed of a particular core. So 1/3 speed is no problem if it's 1/4 the
price (indeed this is the kind of trade-off you'd hope for in an ARM server).

Sadly from the same tweet thread that quote came from: 'All in all: Amazon
having Arm-based offering is a great first step, but it does not seem to be a
particularly appealing one at the moment, (at least for me: especially since
the cost difference is nonexistent if I was to match my existing
performance.)'. So, for this particular application at least, the A1 instances
aren't giving a good cost/performance ratio.

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wmf
_Ultimately it 's the total cost to run your application that's important, not
the raw speed of a particular core._

Not necessarily. A core that's 1/3 the speed can multiply your response time
by 3x.
[https://static.googleusercontent.com/media/research.google.c...](https://static.googleusercontent.com/media/research.google.com/en//pubs/archive/36448.pdf)

~~~
rbanffy
It depends on how CPU-bound you are. If you spend a lot of time waiting for
DRAM, disk or network, then you won't notice.

It's a bit like answering e-mail on a Celeron Chromebook compared to your dual
Xeon Platinum quad Nvidia desktop. You won't notice the difference. 90% of the
time the only difference I notice between my light-and-slow laptop I use for
meetups and conferences and my heavy-and-beefy one is that the puny one has no
built-in fan.

When running Python code, my very methodologically questionable benchmarks
indicate the size of the L1 cache makes a huge difference, so I'll take an
ARM64 box with a Core i9 worth of transistors used as cache over the i9 with
an ARM64 worth of cache any time.

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reitzensteinm
Disk or network sure, but I don't think you can by any reasonable definition
divorce "core performance" from the cache hierarchy and memory bandwidth that
feeds it, at least in the context of the GP's post.

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qalmakka
> non-NUMA Forgive my ignorance, but isn't a "non-NUMA" architecture just UMA?

~~~
tambourine_man
Came here to say the same.

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altmind
More performance benchmarks: [https://www.servethehome.com/putting-aws-
graviton-its-arm-cp...](https://www.servethehome.com/putting-aws-graviton-its-
arm-cpu-performance-in-context/)

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twtw
Anyone know what kind of ARM license Amazon has? Just a processor license or a
full architecture license? I'm curious if Amazon is doing the actual CPU
design.

~~~
wmf
They're definitely using stock A72 cores now. Amazon is very secretive so we
won't know if they're designing their own cores until they ship. (Unless they
post job openings for "custom ARM core designer".)

~~~
twtw
Thanks. I saw it was based on A72, but I couldn't tell if all the discussion
of customization was referring to modifications to the core itself or just the
SoC.

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TazeTSchnitzel
I note that AMD's ARM chip came out not long before AMD must have found out
internally that Zen was very good performance-wise. That's probably why they
stopped working on it. Why compete with yourself?

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syntaxing
I'm more curious on how Amazon makes these chips. Are they just licensing the
Arm IP with some customer specific changes. Then pushing it off to someone
like Global Foundries to manufacture?

~~~
wmf
Yeah, they (Annapurna) license various IP blocks, integrate them, and it's
probably fabbed at TSMC.

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snaky
Discussed
[https://news.ycombinator.com/item?id=18539297](https://news.ycombinator.com/item?id=18539297)

~~~
eganist
What you linked is the original press release. What this story is about is the
development history of the chip.

It warrants its own discussion.

