
Seymour Cray: "Cray-1 Introduction" (1976) [video] - bra-ket
https://www.youtube.com/watch?v=vtOA1vuoDgQ
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hf
Cray's rather famous anti-parallelization quip, "If you were plowing a field,
which would you rather use: Two strong oxen or 1024 chickens?"[0], reminds me
somewhat of one of Donald Knuth's statements: "During the past 50 years, I’ve
written well over a thousand programs, many of which have substantial size. I
can’t think of even five of those programs that would have been enhanced
noticeably by parallelism or multithreading. Surely, for example, multiple
processors are no help to TeX"[1]

[0]
[https://en.wikipedia.org/wiki/Seymour_Cray#SRC_Computers](https://en.wikipedia.org/wiki/Seymour_Cray#SRC_Computers)

[1]
[http://www.informit.com/article/article.aspx?p=1193856&_](http://www.informit.com/article/article.aspx?p=1193856&_)

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akira2501
Well, he built his empire on Emitter Coupled Logic. He didn't have the
limitations of CMOS to deal with and so parallelism wasn't as necessary for
continued computational power.

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weland
I...I'm not sure I understand what you mean, but it feels rude to downvote
based on it. Can you elaborate on that, please?

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sp332
No one is arguing that parallelism is easier or more convenient than serial
processing. (I think.) But clock speeds top out eventually, because power
usage goes up with the _square_ of the clock rate and eventually your chip
just melts. So the only way to get more performance out of a piece of silicon
is to put processors side-by-side.

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weland
I'm not arguing that either, it's the nonsense about ECL and CMOS above that I
can't understand.

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kjs3
It's not nonsense. By committing to using ECL logic (read: cost is basically
no object) Cray didn't _need_ to bother with parallelism to get the best
performance possible at the time, and so it was reasonable marketing for him
to discount it. If he'd been confined to CMOS (or to a somewhat lesser extent
bipolar) logic, he'd have had a very different set of trade-offs to get the
performance he needed.

~~~
weland
> By committing to using ECL logic (read: cost is basically no object)

I don't disagree with your assessment of ECL, but I think you're holding the
historical account upside down :-).

> Cray didn't need to bother with parallelism to get the best performance
> possible at the time

Let's put things into context first: the Cray-1 _was_ a parallel computer. It
had vector processing. That's the most trivial kind of computational
parallelism (at least from a mathematical point of view) and the Cray-1 had
it! Cray not only "bothered" with parallelism, _his supercomputers were as
parallel as they can get_.

However, that wasn't new. There had been vector machines before, like CDC's
STAR-100. However, one of the reason why they failed to gain traction was
precisely the fact they sacrificed serial performance for that. Turns out
that's a really bad, bad, bad idea for scientific computing, because 90% of
the problems that involve cranking matrices usually involve cranking _the
same_ matrices over and over again.

So "the best performance possible at the time" (much like today, ironically!)
turned out to require not only the parallel processing facilities offered by
vector instructions, but also good serial performance, which basically boiled
down to SQUEEZE MOAR CYCLES!! Remember, this was still five years before RISC
became a thing; it was around the time Cocke began designing the IBM 801
(which only became available in 1980!).

At the time, CMOS simply wasn't up to it in that regard. It's not that Cray
made a conscious choice to avoid wrestling with CMOS' limitations, there were
literally no CMOS logic ICs that moved that fast. Not using CMOS was not a
design decision anymore than not using relays was! This was happening at a
time when pretty much _all_ serious computing was done with bipolar logic.
This was still a good two years away from even the faster companies in the
same field (like DEC) abandoned the bipolar logic boat. IBM continued building
mainframes with bipolar logic (albeit using TTL, not ECL) well after that (the
4300 was retired in the early 1990s, although I don't know if they were still
manufacturing it in TTL; but it definitely was in 1979 when it was
introduced!).

When CMOS was adopted later on for high-performance computing later on, it
wasn't because of the costs! ECL's power dissipation demands made it
technically, not economically, unfeasible to make faster logic circuits.

~~~
kjs3
So when shown to be wrong, you redefine the question so you get to be right.
Have fun with that.

~~~
weland
What was the question? I don't see any question mark in the posts above. And
how exactly did I redefine it?

I pointed out that this is wrong:

> Cray didn't need to bother with parallelism to get the best performance
> possible at the time

because Cray not only bothered with parallelism, but _all_ Cray computers were
parallel. And that this is wrong:

> By committing to using ECL logic (read: cost is basically no object)

because cost is hardly the only challenge when working with ECL. And that this
is not only a truism, but also unenlightening from a historical perspective:

> If he'd been confined to CMOS (or to a somewhat lesser extent bipolar)
> logic, he'd have had a very different set of trade-offs to get the
> performance he needed.

First, ECL _is_ bipolar logic, like anything built with BJTs. Second, that
would have also been true if he'd been confined to relays or cranks. Of course
you get a different set of trade-offs if you use a different technology.

But _no computer company at the time_ was building minicomputers, let alone
mainframes or supercomputers, in CMOS! The most megasuperparallel computers of
the time, from the C.mmp to the ILLIAC IV were ECL or TTL. Cray's empire was
built on _precisely the same technological basis_ as that of every other
computer company in the seventies.

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mark-r
I had the pleasure of touring the Cray plant in Chippewa Falls and meeting the
man himself, not too long after this talk. My expectations were that we would
be on one side of a glass window and the computer would be on the other, but
no - we walked right up to one that was being tested for delivery, serial #5 I
believe it was. They were obviously proud of the cooling system - we were
invited to put our hands on the side panels to see how cool it kept. The wire
maze on the inside of the "C" was incredible, one trip would have caused an
immeasurable amount of damage.

Unfortunately we only met Seymour for a short time, obviously he was quite
busy. Even more unfortunate is that I don't remember much of that meeting. The
only tidbit I remember clearly is him pointing to a pumpkin on his desk. His
daughter had grown it in the garden, and knowing he was already thinking about
a Cray 2 machine decided it should be named the "Cray 3".

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at-fates-hands
My father recently told me he used to share lab time with Cray when he was in
college. He said people would go crazy when he was on campus and follow him
wherever he went.

He said he was like the Steve Jobs of his day - if you were into tech, you
knew who he was and just wanted to soak up what he was saying.

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GuiA
Tangentially related but I had to share:

 _Another favorite pastime [of Seymour Cray] was digging a tunnel under his
home; he attributed the secret of his success to "visits by elves" while he
worked in the tunnel: "While I'm digging in the tunnel, the elves will often
come to me with solutions to my problem."_

[https://en.wikipedia.org/wiki/Seymour_Cray#Personal_life](https://en.wikipedia.org/wiki/Seymour_Cray#Personal_life)

~~~
frik
I read about it in the "Supermen" book [1], he dug extensive tunnels. Doing
repetitive work makes it probably easier to do daydreaming. That's how he
designed his Cray super computers architectures in his head.

[1] [http://www.amazon.com/The-Supermen-Seymour-Technical-
Superco...](http://www.amazon.com/The-Supermen-Seymour-Technical-
Supercomputer/dp/0471048852/)

~~~
kjs3
Some geniuses take long walks for inspiration, some dig tunnels and talk to
elves. I don't judge.

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kabdib
We had a Cray at Apple. I got an account on it and mucked with it for a while,
but nothing serious. Its main use was to simulate plastic flow in molds for
the cases of Macintosh computers (molds are pretty expensive, $500K to $1M,
and you want to make sure they'll work well before you commit to making them).

Turned out that Seymour used MacDraw to design parts of the Cray-3. So we were
using each other's computers to design our own computers....

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guiambros
I had the opportunity to use a Cray Y-MP 2E at University, early-90s. Even
though this was in Brazil, you had to get special approval from the US
Government to be able to run your code. I got a free pass as I was limited to
10 mins of CPU time/week. Shell usage didn't count, so 10 mins was plenty of
time to play with UNICOS.

It was a beautiful machine. The C-shaped purple machine was impressive, and
the refrigeration huge. And we had some nice SGI Indigo workstations as the
front-end, so you could optimize your (Forth) code before moving to Cray.

Amazing to think of all that paranoia for 666 Megaflops. My not-so-new Core i7
has 150,000+ Mflops, not counting the GPU.

~~~
kjs3
I got to use a Y/MP-48 (COS with VAX/VMS front ends) in the late 80s.
Excellent learning experience. The professor offered something like 10 bonus
points on the final for anyone that could solve a particular problem (don't
recall which one) in a faster time than he was able to achieve. Having done
the best I could, I called the local Cray office looking for help. It was a
sales office, so the person I talked to could only say he'd see what he could
do. A couple of days later, they called and asked if I could come to the
office for a bit. Turns out, one of the senior compiler engineers was in town,
and he took something like 2 hours out of his trip to teach this college kid
all the black magic and voodoo compiler switches and optimization techniques
that weren't covered in the class. Very generous and great customer service. I
ended up about 12% faster than the shocked professor, and got my A.

~~~
guiambros
Love the story, thanks for sharing it.

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dang
This is splendid! But definitely not Cray's "only surviving talk", since
YouTube recommends another:

[https://www.youtube.com/watch?v=jG63r4e6eb8](https://www.youtube.com/watch?v=jG63r4e6eb8)

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alayne
The only good book on Cray I've found is he Supermen: The Story of Seymour
Cray and the Technical Wizards Behind the Supercomputer by Murray.

Besides two or three videos, The Supermen, and tangentially related books
about the history of CDC, it's hard to find a lot of details about Cray's
work. I think the University of Minnesota has some Cray related papers, but
I'm not sure what.

~~~
pico303
I loved Supermen. A little light on the technical, but a really fascinating
read, particularly if you're into the history of computing.

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RustyRussell
I'd love a transcript of this talk: the audio is poor...

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ChuckMcM
It is very amusing though to turn on Google's auto close captioning though :-)
(my way of agreeing with this request)

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cl8ton
Great seeing this again. I remember in its day Cray was like a mythical beast
we only heard of since Gov was the only one with enough money to buy one.

The C configuration with hard wrapped wires were awesome. Hard wrapping was
the fastest path for electrons from point A to B.

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hcarvalhoalves
What is "hard wrapping"?

PS: No kidding, can't Google it. I only find articles about jewelry instead.

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cl8ton
Back in the bread boarding days, hard wrapping was using a tool to physically
wrap a hair thin insulated wire from one pin on an IC to another pin on an IC.

Not using the PCB foil electrical path but rather a direct short path as
possible wire connection between two points.

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mikeash
Is this another term for wire wrap, or is it something different?

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cl8ton
Yes wire wrapping and hard wrapping the same thing.

Hard wrapping was something the current day mags called it (Popular
Electronics) for one.

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danjayh
What an amazing speaker. He brings what should be boring technical details to
life in an engaging, humorous dialogue. Obviously a very technically
intelligent man, and an excellent public speaker, that seems like it's a rare
combination.

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localhost
Amazing what ~40 years can do. I still find it astounding that my Snapdragon
800 powered phone, a Lumia 1520, is ~800x (130 GFLOPS vs. 160 MFLOPS) faster
than the Cray-1 and ~1/24000th the mass (5.5 tons vs. 209g). Truly a
"supercomputer in your pocket". Which plays various flappy bird clones. Or
Wordament.

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protomyth
I still think two of the great tragedies of modern computing were the loss of
Seymour Cray and Jay Miner.

[edit: I still have a picture of me standing in the middle of a Cray 2 - that
was a fun machine]

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tom_jones
Thanks for posting. Seymour Cray is one of my heroes. Great man with great
vision. Such a great loss to the world.

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kylek
This talk is an absolute gem. Thank you.

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kichu37
nice

