

Is Koomey's Law eclipsing Moore's law? - mikecane
http://www.economicsofinformation.com/2011/09/is-koomeys-law-eclipsing-moores-law.html

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wmf
Exponential increase of transistor power efficiency was predicted by Dennard's
scaling laws, so it sounds like Koomey has just empirically verified it. It's
an interesting time to publish such a study, though, considering that everyone
is discussing the _end_ of Dennard scaling.

[http://www.ieee.org/portal/cms_docs_societies/sscs/PrintEdit...](http://www.ieee.org/portal/cms_docs_societies/sscs/PrintEditions/200701.pdf)

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thetwentyone
A link to the real article from MIT's Technology Review:
[http://www.technologyreview.com/printer_friendly_article.asp...](http://www.technologyreview.com/printer_friendly_article.aspx?id=38548)

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bebop
Why does everyone get Moore's law wrong? He said: "The number of transistors
that can be placed inexpensively on an integrated circuit doubles
approximately every two years". I guess that "Computing Power" and transistors
are related, but he was really just talking about more transistors on the
chip.

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dfxm12
Are these two laws even mutually exclusive?

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a-priori
Only if you assume that there's a one-to-one correspondence between
transistors and processing power. That is, it doesn't take into account
improved microarchitecture (e.g. speculative execution, pipelines and cache
management) that more efficiently use a given number of transistors.

~~~
Someone
Isn't the different architecture more of an "if you want to meaningfully use
more transistors, you will have to do it something differently" than of an "we
can do faster if we do things differently?"

I would expect that any micro-architecture effects would be relatively
marginal, relative to the rough number Moore's law gives.

So, I think, at the resolution of Moore's law, "number of transistors double"'
and "processing power doubles" are equivalent.

Another related 'law' is "CPUs gain a bit every 18 months". That metric
predicts 6 years between outgrowing 4 bits and outgrowing 8bit CPUs, 12 years
before needing 16 bits, 24 for needing 64 bits, and indicates we will not need
a 128bits CPU on the desktop before 2050 or so (of course, all if we manage to
stretch Moore's law that far)

I think that is in the right ballpark.

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frankus
There is a striking parallel between this and American cars in the 50's and
60's, when the focus powertrain-wise was simply to get as much power out of an
engine at the least possible cost, efficiency be damned.

So mobile devices are sort of the Arab Oil Embargo of computing.

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sliverstorm
It seems to me like 'Koomey's Law' is just an emergent property of Moore's
Law.

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sp332
Not entirely, do you remember Intel's NetBurst fiasco in early Pentium 4 CPUs?
[https://secure.wikimedia.org/wikipedia/en/wiki/Netburst#Succ...](https://secure.wikimedia.org/wikipedia/en/wiki/Netburst#Successor)
Power usage is free to increase until you physically have trouble removing
heat as fast as you're generating it. Today, you can crank a i7 CPU to 4.0GHz
without much trouble, if you have decent cooling. The architecture affects
both performance and power consumption. Just having smaller transistors isn't
the whole story.

