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Comment by Houshalter | Hacker News Reader

Their competitors are also affected.

Also a 30% decrease is also equivalent to setting Moore's law back 7 months. A 5% loss is only setting it back 1 month. I know that's a bit of a naive calculation. But the point is computing power has long operated in an exponential domain. So big differences in absolute numbers aren't necessarily a big deal.

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According to this patch comment, AMD x86 chips are not affected: https://lkml.org/lkml/2017/12/27/2

Sure but who is using AMD chips in place of Intel server chips? If company A competes in the widget market against company B and they both built their server infrastructure on Intel then neither company gained an advantage due to a performance degradation in Intel hardware.

> Sure but who is using AMD chips in place of Intel server chips?

Well... Everyone who bought AMD. Some people managed to see beyond the hype and go for the optoon that made sense.

The overwhelming majority of the cloud runs on Intel. Saying AMD is slightly better off doesn't really help if my systems are built on Intel. This is the case for most people.

What hype are you referring to? Are you suggesting the people who bought AMD knew this was a problem for Intel?

Azure got some AMD EPYC.

>Sure but who is using AMD chips in place of Intel server chips?

Maybe a lot more now?

CPU speed hasn't followed Moore's law since 2003ish. (Number of transistors is still following Moore's law, but that doesn't necessarily directly help you when your program is suddenly 3-30% slower.)

A CPU from 2017 is going to run your programs a hell of a lot faster than one from 2003. Even if they technically have the same clock speed. Look at benchmarks for instance: https://www.cpubenchmark.net/high_end_cpus.html

The claim wasn't "CPUs in 2017 are not faster than CPUs in 2003" or even "CPUs in 2017 are not much faster than CPUs in 2003"; the claim was that they haven't followed Moore's law since 2003, so applying it to CPU speed nowadays is inaccurate. Of course CPUs are faster now than they were 14 years ago, just not as fast as the case where Moore's law still applied to CPU speed.

Moore’s Law doesn’t describe CPU clock speed increases.

Dennard scaling however did deal with clock speed (indirectly via power). It has failed since about 2005.

I don't think you can reliably phrase this in terms of Moore's law. Moore's law mostly concerns raw FLOPs. It's less useful for predicting hardware performance for operations that are governed by limitations like I/O and memory latency. And this slowdown, if I understand it correctly, is largely driven by memory latency.

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