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A comment on A Deep Dive into AMD’s Rome Epyc Architecture. Parent comment

Re:A Deep Dive into AMD’s Rome Epyc Architecture by ajross on Saturday August 17, 2019 @10:33AM (#20724212)
Tools like that are a core part of the design process. You write that software along with the choice of parametrization of the design. It's not an off the shelf thing. But yes, that's how it works.

It's also important to note that decisions like this are hugely workload-specific. There's no single best processor for all applications. In extreme examples: almost every transistor on a vector SIMD unit is wasted when trying to optimize for a client Javascript benchmark; streaming symmetric encryption gets no benefit from L3 cache (which is like half the chip these days!); etc...

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Re:A Deep Dive into AMD’s Rome Epyc Architecture by mmrezaie on Saturday August 17, 2019 @10:39AM (#20724244)
Do people like Jim Keller are the experts in finding the right balance? Is that why he and his team are so important?
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Re:A Deep Dive into AMD’s Rome Epyc Architecture by zazagura on Saturday August 17, 2019 @10:52AM (#20724311)
Maybe the time has come for applications specific CPU variations?

One optimized for node.js tasks, one for databases, ...

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Re:A Deep Dive into AMD’s Rome Epyc Architecture by snaky on Saturday August 17, 2019 @11:07PM (#20727982)
Mainframes used to explore this long ago, leveraging different microcode for different workloads keeping the hardware of processing unit the same, https://en.wikipedia.org/wiki/ZIIP

On the other side of the computing spectrum, there were a couple of papers in 2010s about offloading most common mobile tasks (like CSS layouting) to the specialized mobile CPU subsystems. Maybe this should have been implemented if Google made their own mobile CPU.

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Re:A Deep Dive into AMD’s Rome Epyc Architecture by pjc50 on Saturday August 17, 2019 @07:09PM (#20727034)
ARM got a Javascript oriented instruction: http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc....

At least two different tasks, audio and graphics, have special application specific processors. Networking and crypto are also often offloaded.

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Re:A Deep Dive into AMD’s Rome Epyc Architecture by tempguy9999 on Saturday August 17, 2019 @11:59AM (#20724630)
> one for databases

as a DB guy, there's no 'one task' for DBs . The only thing I can think that is nearly characteristic of DBs I've worked on is that they're IO bound.

That's possibly true of most things except Floating point and graphics.

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Re:A Deep Dive into AMD’s Rome Epyc Architecture by snaky on Saturday August 17, 2019 @11:15PM (#20728012)
While that's true, you can achieve impressive results offloading particular parts of particular DBMS code to the specialized CPUs, https://www.ibm.com/support/knowledgecenter/en/SSEPEK_11.0.0...
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