
A reprieve for Moore’s Law? Work on gallium nitride semiconductors - bootload
http://arstechnica.com/information-technology/2016/06/cheaper-better-faster-stronger-ars-meets-the-latest-military-bred-chip/
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akuma73
It's not as if Intel and others haven't looked at this and other III-V
materials.

These GaNs seem to be more suited towards amplifiers and a replacement for the
kinds of components that GaAs is currently used - not digital logic.

For a look at a potential III-V materials for use in digital logic, have a
look at this article. [http://www.extremetech.com/gaming/203926-analyst-intel-
will-...](http://www.extremetech.com/gaming/203926-analyst-intel-will-adopt-
quantum-wells-iii-v-semiconductors-at-10nm-node)

IMHO, Moore's Law will end in about 2019-2020. No exponential can go on
forever. This will have huge ramifications for silicon valley. You're already
seeing a slow-down. Ever wonder why Intel chips aren't getting all that much
faster?

~~~
api
My take on what it will mean:

(1) It will now make sense to invest in the development of higher-order
compute architectures that take advantage of truly massive parallelism. In the
past such efforts (connection machine, etc.) were killed by Moore's Law-- by
the time they hit the street CPUs had already gotten so much faster their
advantage had disappeared.

(2) It will also make sense to prioritize parallelism in software to a much
greater degree than it has been historically.

(3) "Software Moore's Law" type efforts will get a huge boost. In the past
we've almost had an "Eroom's Law" in software: it bloats in proportion to
faster chips and more RAM. Expect to see performance in software become a real
feature. (I think we're already seeing this.)

(4) Slow languages will become considerably less shiny. Fast languages that
take good ideas from slower dynamic languages like Rust, Go, Swift, etc. will
become much shiner. C/C++ might also see a renaissance in mainstream interest.
(This is already happening.)

(5) Once fabs all catch up to the state of the art endpoint fab tech for
conventional chips, silicon fabrication will become a commodity service
subject to commodity market forces. It will get _cheap_. This will accelerate
even more as patents expire (or China ignores them).

(6) China (and specifically the Shenzhen ecosystem) has a _very_ good chance
of eating semiconductors due to #5. Nobody does manufacturing scale like the
Chinese and once they catch up they'll own it unless players like Intel get
serious about getting ahead of this.

(7) Also due to #5, the price per unit of compute may continue to fall for
some time after Moore's Law hits the wall -- and partly _because_ Moore's Law
has hit the wall. Something akin to the current top-end Xeon could easily cost
under $20 in 10-15 years. Smallish ARM chips could be priced by weight like a
building material.

(8) As a consequence of #7, we might see what I call "Moore's Mushroom" \-- a
geometric fall in the price of massively parallel machines (also see #1). If
the equivalent of a 48-core Xeon is $20, then a 1200-core monster might cost
under $1000. For $10k you'd be able to buy your own equivalent of a decently
sized data center.

(9) Power efficiency of chips may continue to improve for a while to the
extent that this can be pursued without increasing density, and it might make
sense to make this a huge priority once density is stable. Power/compute might
still have a ways to go.

(10) As a consequence of #5, open source core designs will really hit the
mainstream. You'll be able to take an open reference chip design and have it
fabbed by the lowest bidder. "White label" OSS chips will appear.

(11) Finally, also due to #5 ASICs will get cheaper to make. Expect to see
more of them, especially since it will now make sense to make an ASIC to speed
up an algorithm as you can no longer just wait on Moore's Law to give you that
speed for free. You'll see AI ASICs, crypto ASICs, graphics ASICS, data
compression ASICs, even language specific 'accelerator' ASICs like JavaScript
coprocessors, etc. With OSS core chip designs these could easily get bolted
on, leading to weird custom cores like a "JavaScript optimized OpenRISC white
label CPU."

(12) It might still be possible to push single-threaded performance by
improving cooling, e.g. by mainstreaming liquid or active refrigerated
cooling. The current overclocking record for cryogenically cooled Xeons is
around 6.2ghz. Will we see liquid nitrogen in data centers as a common thing?

(13) The PC and mobile device upgrade cycle will slow _a lot_ , which will
further kill profits in hardware all the way up the stack. Hardware's about to
become a _hard_ business.

TL;DR: price/compute and power/compute will continue to improve for a while;
semiconductor margins will get squeezed; software efficiency will matter more;
ASICs will get more common; open source chips might finally arrive.

All of this might actually be good for Silicon Valley, which mostly does
software not hardware. Software's about to get even more important.

~~~
akuma73
Great list! To quote Bob Colwell (former Intel fellow and DARPA director),
it's hard to replace an exponential. There will be non-uniform improvements
and "one-off" type of breakthroughs but a sustained 2x every 2x years is just
not going to happen ever.

As a thought experiment, what if Moore's Law scaling had ended in 2000? No
smartphones.

I agree that the value of software engineering and computer architecture in
general will increase as the transistor-scaling free ride ends. We have to
make more efficient use of existing transistors that will no longer scale
going forward.

~~~
api
Quibble: I disagree about 'no smartphones.' Look at what is possible on a
64K/8-bit machine in the 1980s:

[https://en.wikipedia.org/wiki/GEOS_(8-bit_operating_system)](https://en.wikipedia.org/wiki/GEOS_\(8-bit_operating_system\))

An iPhone could be done on a single core 100mhz system _if code is efficient_.
That would mean forfeiting some amount of eye candy and developing more
efficient GUI layers.

I do agree that some smart phone functionality like super-high-end 3d maps
apps might not exist, but a basic map with basic turn-by-turn directions could
be built for the Commodore 64 by programmers who actually think about
performance.

This is why I think a "Software Moore's Law" and performance is going to
matter _a lot_. Premature optimization might no longer be the root of all
evil. It might be a skill programmers need to have.

~~~
akuma73
I agree here with the word "possible".

However, progress on this front would be slow due to the increased cost of
software development. Software would be much more difficult to write leading
to longer lead times for applications.

I don't think the app stores would scale at the same rate that it did for
iPhone or Android.

One analogy is parallel programming. This is generally very difficult, so
people avoid it, even when hardware vendors give you get a bounty of cores.
Another example is GPGPU - very slow progress on mapping data-parallel apps to
the GPU (image processing etc.).

We may not know what future devices and applications are not possible due to
Moore's Law's end. Another example is the recent explosion in deep learning -
this was only possible due to the increase in FLOP density as a direct
consequence of Moore's Law. These algorithms were around in the 80s.

~~~
api
"Software would be much more difficult to write leading to longer lead times
for applications."

This is a problem we will need to solve. So far we've increased programmer
productivity by sacrificing code efficiency because Moore's Law gives us more
speed for free. We'll have to find ways to reduce this trade-off in the future
by thinking harder and deeper about software since the hardware's not going to
save us anymore.

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ridgeguy
Another wrinkle in GaN semiconductors is GaN RF power transistors with grown-
on diamond heat spreader layers. Increases RF power density by 3x over GaN on
SiC. Brief overview here (2014):

[http://www.edn.com/design/wireless-
networking/4435899/Histor...](http://www.edn.com/design/wireless-
networking/4435899/History-of-GaN-on-Diamond-Technology)

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petra
As far as i can tell this has no relation to moore's law. Moore's law
currently suffer mostly due to:limits of manufacturing small things, and
mostly because of energy consumption and delay of wires. Without solving
those, it would be hard to offer big improvements.

And GaN can't solve those afaik.

~~~
jacquesm
For a given size transistor the GaN element will switch considerably faster
than the Silicon equivalent. We have an enormous amount of knowledge about the
Silicon based process though and it's a bit like trying to come up with a
better combustion engine: it may not be the best material to begin with but it
will be very hard to catch up with 50 years of materials science and process
technology on Silicon. It's a huge head-start, but I'm happy that people are
looking at alternatives to Silicon. Bismuth based compounds are interesting as
well.

~~~
petra
Sure it's great that people research things.

>> For a given size transistor the GaN element will switch considerably faster
than the Silicon equivalent.

Most of the delay today is because of wires, not transistors.

See figure 1 at
[http://www.monolithic3d.com/blog/previous/3](http://www.monolithic3d.com/blog/previous/3)
.

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nemock
Maybe this shouldn't have been called a law. Maybe, "Moore's observation" or
"Moore's postulation" would have been more apt.

