
Smaller, Faster, Cheaper, Over: The Future of Computer Chips - ganeumann
http://www.nytimes.com/2015/09/27/technology/smaller-faster-cheaper-over-the-future-of-computer-chips.html
======
CydeWeys
I remember reading articles like this a decade ago saying that transistors
couldn't get any smaller because they were already the size of visible light.
We've since switched to UV light per this article, and there's still much
shorter wavelengths available. The size of the atoms that make up the wafer
itself could be a potential problem too, but there's other materials we can
switch to that are less susceptible to quantum tunneling. And that's not even
touching true 3D chip design (right now it's a pile of layers that is
essentially 2D).

Point being, there's many billions of dollars in revenue here at stake, and
chip companies are doing their damnedest to solve these problems. They've
solved every challenge so far, and there's no real reason that these latest
challenges are fundamentally unconquerable in ways that the previous ones were
not. An article highlighting the current challenges is useful, but one
positing that they can't be overcome is sensationalist.

~~~
kragen
On the contrary, this article omits mentioning most of the limits we're
running into, probably because the reporter couldn't understand them. Dennard
scaling ended almost a decade ago because of leakage. You can still put more
transistors on a chip, but the benefit of doing so is going away: it allows
you to put more hardware in there, but you can't afford to run it all the time
because it overheats (the "dark silicon" problem), so instead of giving you a
parallel speedup, you're limited to providing a wider range of alternative
hardware resources. Reversible computing was an attempt to solve the power-
dissipation problem, but it doesn't help with leakage currents, and it's also
essentially unachievable as a practical reduction in dissipation with current
technology.

(I think it's a little strange to call light with a wavelength of under 10nm
"ultraviolet". It's 40 times more energetic than the single octave we call
visible light; that's five or six octaves away. I think it's usually called
"X-rays".)

True 3D chip design is older than 2D chip design. Bardeen and Brattain's
transistor was a 3D chip. That's why it was impractical for 12 years until the
planar fabrication process in 1959. Planar fabrication is not only technically
important, but also necessary for our current approaches to cooling, which is
getting gradually more crucial.

I agree that we're not even close to the ultimate limits of computation. If
your lambda is 10 nm and your wires are 20 nm across, that's still on the
order of 200 atoms across, and it's been demonstrated that you could just use
one: that's almost 16 Moore doublings, or 32 years. And certainly when we
figure out how to do reversible computation and molecular nanotechnology, we
can reach that limit. But CMOS and X-ray lithography aren't on a path to do
that.

CMOS had a great run, totally dominating electronics from about 1982 to about
2017, pushing every alternative process to the margins with its low cost and
the miracle of Dennard scaling: ECL, Josephson junctions, CCDs, DNA computing,
vacuum tubes, core, chalcogenide glasses. But now that's over.

But don't forget that electronics started in 1904. Vacuum tubes, planar
bipolar transistors, planar bipolar ICs, and planar CMOS ICs have each had
their time in the sun. Whatever comes next will be something totally
different, maybe as different as vacuum tubes are from planar transistors, and
there's no reason to expect Intel or TSMC to be the one to pioneer it, just as
Polaroid, Kodak, and Nikon weren't the companies that pioneered semiconductor
imaging sensors or flash memory.

I'd be surprised if it happened in the US or Europe. Israel, China, Korea, or
Japan, possibly.

~~~
ChuckMcM
Excellent summary, note that the deep trench transistors (aka FinFets) helped
with the leakage problem significantly, but heat will always be an issue.

I've speculated that if we could figure out how to manufacture it, we could
get electron scale computation out of an artfully constructed Graphene matrix.
Basically a tiny Pachinko machine with electrons for balls. But at that scale
you're going to need redundancy to get around quantum effects. We know you can
build transistors at 7nm [1] but to what end.

[1] [http://arstechnica.com/gadgets/2015/07/ibm-unveils-
industrys...](http://arstechnica.com/gadgets/2015/07/ibm-unveils-industrys-
first-7nm-chip-moving-beyond-silicon/)

~~~
kragen
Thank you for both the plaudits and the corrections!

------
lsc
Now, I'm not even close to being able to weigh in on the physics side here...
but my observation, as someone who has spent several hundred grand on servers
in the last decade is that Intel is run by profit-maximizing professionals.

Look at how much better/faster/cheaper the intel stuff got after AMD's release
of the hyper transport opteron.

and look at how much Intel tried to collect rent from their position of market
dominance (say, by making us buy rambus and then FBDIMMs) before that.

AMD needs to step up their game.

There's another market force at work, too, and that is demand. On the consumer
side of things, at least, there isn't any need for faster x86 computers,
because Microsoft isn't doing it's job. It used to be that every three years,
Microsoft would release another office suite that everyone needed, that ran
like a dog if your computer was more than a year or two old.

I just upgraded my games box, a decade-old core2duo, to windows 10. Works fine
(modulo spyware bullshit) - Microsoft has been focusing on the "mobile" market
and has been putting a lot of effort into slimming down.

That, and (and I'm so shocked to say this) but it turns out that the people
crowing about 'mobile is the future' were mostly right. When I was in high
school, even my poor friends had desktops. Now, I know a _lot_ of people, even
technical people who only have laptops... and a lot of the people I went to
high school with got rid of their desktops and now only have cellphones and
tablets; nothing with a full keyboard and intel CPU at all.

If that trend continues, I would predict that we'll eventually switch our
servers to whatever architecture the mobile devices use. AMD and Cavium and a
handful of other companies have been talking about doing that with ARM, but so
far there's nothing I can buy except at engineering sample prices.

~~~
achamayou
You can buy HP Moonshots with ARM cartridges for relatively realistic prices.
PayPal is supposedly running some of their stuff on them.

~~~
lsc
I do not have the energy to go through sales... what is 'realistic' here?

And can they compete in cpu power per watt with the Intel Xeon D boards I can
get from my local supermicro distributor? they look pretty sweet; the only
real problem is the four dimm limit; I'm seriously considering those and 32gib
modules right now, just because they have such a nice watts per flop.

Long-term, for it to be a realistic solution, I'll need to be able to buy
compatible parts from different companies.

~~~
achamayou
Sorry, I can't say exactly. You can find R120-P30 1U boxes at GBP1500 (8core
8DIMMs) [http://www.scan.co.uk/products/gigabyte-r120-p30-single-
sock...](http://www.scan.co.uk/products/gigabyte-r120-p30-single-
socket-1u-rackmount-armv8-24ghz-pcie-30-8x-ddr3-slots-ecc-unbuffered-2x-10g)

Higher density systems like Moonshot or H270-T70 are cheaper per core of
course, whether they're competitive depends on your specific application.
They're not at the point where they're commoditized and where you can buy
parts easily though.

~~~
lsc
hm. $2200 in the money I use, or so. hm. the xeon D is around half that just
for the board and cpu (with four dimms, but also with 8 cores... presumably 8
more powerful cores) - and after that it's just a matter of sheet-metal and a
psu, so if you can deal with half the dimms, the xeon d is lower capital cost.
(I mean, you _can_ spend a grand on a psu and a case, but you have to try
pretty hard.) - but the real world power usage could make the difference. Hm.
Things are often cheaper priced in USD, too.

So... yes. more research is required. But thanks! I wasn't aware that gigabyte
was actually shipping it's arm stuff to mortals. Hm. I still don't see it in
any of my usual (USian) channels; nothing on provantage. Still, pretty cool
stuff.

~~~
makomk
The performance and performance-per-watt of the X-Gene1 processor that thing
uses don't look terribly competitive, unfortunately:
[http://www.anandtech.com/show/9185/intel-xeon-d-review-
perfo...](http://www.anandtech.com/show/9185/intel-xeon-d-review-performance-
per-watt-server-soc-champion/9)

Apparently it's made on a 40nm process, and it's probably not a terribly well-
optimised design either, both of which go some way to explaining why it's not
much good. (Though I guess it was good enough to convince Intel to release the
Xeon D for a reasonable price. As you say, Intel's run by profit-maximising
professionals - they can resoundingly beat any ARM server chips anyone puts
out and drive them out of business, they just don't release their best chips
at the best price unless they have to.)

~~~
lsc
Yeah, the xeon D chips are the only 13nm xeons out. Funny that. At least they
didn't gimp it as hard as they gimped the E3 xeons. Sure, only four ram slots
is the same... but on the e3 it maxes out with 8gb dimms. here, at least I can
use 32gb dimms, which are coming down in price, and get a semi-reasonable 128g

------
transfire
10 years? It has already happened. Consumer chips haven't gotten much better
in a decade. Most gains have been applied to power efficiency for mobile use.
An unfortunate side effect is the that chip makers are learning that they can
milk money for smaller improvements. I doubt we will ever return to the old
<2yr Moore's law.

On the upside we might get lucky and some new innovations will come along an
give us a quick bump. Tech like optical interconnects, 3D chip manufacturing,
memristors, etc.

~~~
CydeWeys
Huh? Moore's Law is about transistor density, not clockspeed. It absolutely
hasn't paused over the past decade. See here:
[http://education.mrsec.wisc.edu/SlideShow/images/computer/Mo...](http://education.mrsec.wisc.edu/SlideShow/images/computer/Moores_Law.png)

Processors have also gotten significantly more capable over the past decade,
and if you don't believe me, go use an Athlon 64 X2 for a bit (the cream of
the crop from 2005) and see how that compares to today's processors. Poorly.

~~~
CydeWeys
And here's a representative comparison if you want to see actual benchmarks
that measure real work that processors can perform:

1\. THEN: AMD Athlon 64 X2 3800+
[http://www.cpubenchmark.net/cpu.php?cpu=AMD+Athlon+64+X2+Dua...](http://www.cpubenchmark.net/cpu.php?cpu=AMD+Athlon+64+X2+Dual+Core+3800%2B)

2\. NOW: Intel Core i7-5820K
[http://www.cpubenchmark.net/cpu.php?cpu=Intel+Core+i7-5820K+...](http://www.cpubenchmark.net/cpu.php?cpu=Intel+Core+i7-5820K+%40+3.30GHz&id=2340)

Note that the modern one is 13 times faster, and came out about nine years
later. Sounds like Moore's Law is alive and well to me.

~~~
shawn-furyan
I think the more illustrative comparison is with the i7 920, which came out in
2008. In the intervening 7 years, there's only been a ~160% improvement by the
standard given. That's a rate of 23% improvement per year, rather than the
130% per year that your example implies. Most of the improvement from the
Athlon 64 X2 3800+ to current CPUs was concentrated in the release of the
Nehelem architecture.

[http://www.cpubenchmark.net/cpu.php?cpu=Intel+Core+i7+920+%4...](http://www.cpubenchmark.net/cpu.php?cpu=Intel+Core+i7+920+%40+2.67GHz&id=834)

The i7 920 was an incredible step forward, but progress has stalled since its
release.

------
knowaveragejoe
I have little experience with hardware but I've often wondered about this.
Chip manufacturers seem to be trying to fit more and more into an amount of
space that continues to shrink. Why not stay at, say, 1x1" and fill that space
out? I'm sure there's a good reason why not, heat or density of the
connections or somesuch. I'd love a more thorough explanation however, if
anyone knows.

~~~
yk
Because they want to fit as many dies as possible onto a wafer. The cost for
lithography is largely per waver, so if they can cut more chips from a single
waver, that is, if their chips are smaller, they can increase their profit per
wafer.

~~~
mpweiher
That and smaller geometries tend(ed) to get faster (the electrons have to
travel smaller distances) and consume less power to boost. Win win win.

This is why Intel used to beat out much better processor architectures simply
by having enough money to always be at least 1 fab generation ahead.

~~~
irl_zebra
Forgive my ignorance, but if the fab generation ahead was already invented,
and (my understanding is) a new fab process requires completely new machinery,
what stopped AMDAMD, whoever, from "skipping" a generation to catch up with
Intel?

~~~
makomk
As I understand it, every fab generation requires a bunch of changes and new
tricks, but they're generally in different areas of the process - and you need
most or all of the tricks learnt in creating the previous generation of fab in
order to build the one after that. So you probably don't save all that much
time or money by skipping a generation, and in the meantime you're a
generation further behind and have nothing competitive to sell.

------
kurthr
If you want actual industry discussion, I recommend SemiWki articles 1-5 by
Scotten Jones.
[https://www.google.com/url?q=https://www.semiwiki.com/forum/...](https://www.google.com/url?q=https://www.semiwiki.com/forum/content/4522-moore%25C2%2592s-law-
dead-long-live-
moore%25C2%2592s-law-%25C2%2596-part-1-a.html&sa=U&ved=0CAsQFjACahUKEwiysrCN_ZfIAhXNm4gKHSrHB2U&client=internal-
uds-cse&usg=AFQjCNGBP3nSK_NfMlkzNiX7T3E-haYRCg) (my apologies on the link, but
the direct one I tried did't work without login) The issue isn't Moore's law
(either speed or #transistors), the issue is cost per transistor. If that
doesn't scale we aren't going to double the price we pay to get 2x more cores.
Power/Cooling and the increasing cost of fabs has also put a dent in things.

------
max-a
Do you know more sources where I can read about IC manufacturing? Gwern's
article [0] spurred my curiosity about the topic. EE senior here.

[0][http://www.gwern.net/Slowing%20Moore%27s%20Law](http://www.gwern.net/Slowing%20Moore%27s%20Law)

~~~
hga
While it's dated (e.g. just prior to what people are saying are the heydays of
CMOS, which matches my vague memory), I found this 1981 book invaluable back
when I read it in the early '80s: [http://www.amazon.com/Microelectronics-
Revolution-Tom-Forest...](http://www.amazon.com/Microelectronics-Revolution-
Tom-Forester/dp/0262560216/)

It covers in at least a little detail all the generations of semiconductors,
e.g. there was a great table showing which companies were big in each. As I
recall, back then TI was the only survivor, and, surprise, TI is still pretty
strong as I understand it. It's discussions and illustraions of yield, what
akiselev discusses here
[https://news.ycombinator.com/item?id=10286735](https://news.ycombinator.com/item?id=10286735)
were particularly useful.

I wouldn't recommend it today (and probably didn't return to it after the
'80s) except that's it pretty cheap used and will cover lots of stuff that's
not so generally well known now.

------
DannoHung
Are gallium based chips completely non-viable or something? I thought they
were the next big thing in chip materials that would let us get past the
Moore's law restrictions in silicon?

~~~
kragen
According to the USGS, gallium arsenide use is higher than ever, but it
remains niche, because it's just a minor tweak to the silicon bandgap
structure, especially for bipolar circuits, where people have been fabricating
high-performance CPUs in it since the 1980s. It doesn't work even adequately
for CMOS, but even if it did, it doesn't solve the problems with Dennard
scaling.

If you're looking for exotic materials to bail us out, it might be a little
less hopeless to look to diamond or to high-temperature semiconductors.

~~~
vjoshi
I thought (and forgive me if I'm wrong, not a big area for me)... but Denard
scaling fell apart cira 2004? Aah unless that's what you mean, about not able
to scale oxide thickness / voltage etc

~~~
kragen
exactly.

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CmonDev
Searched for 'parallel' and 'core' on the page - no matches found.

