
The Cray 2 Super Computer (1985) [pdf] - ChuckMcM
http://archive.computerhistory.org/resources/text/Cray/Cray.Cray2.1985.102646185.pdf
======
guiambros
I had the opportunity to use a Cray Y-MP 2E at university in the early 90s. At
the time there were strict export restrictions, so I had to get a special
approval from the U.S. Government (this was in Brazil).

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

In hindsight, it's ironic to think about all the paranoia and secrecy - for
just 666 Megaflops. My not-so-new Core i7 has 150,000+ Mflops, not counting
the GPU.

~~~
seanp2k2
Ahh yes, modern computers put these older systems to shame in some regards,
but what did the typical desktop have back then?

There's a person out there who made a 1/10th scale cycle-accurate
Cray-1A...which is truly _pretty cray_ [http://www.chrisfenton.com/the-
numbotron/](http://www.chrisfenton.com/the-numbotron/)

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ChuckMcM
I find it interesting to review and contrast the architecture of super
computers with modern day processors. The clock speed and memory quantity are
higher, but often there are large differences in memory bandwidth and I/O
bandwidth. This shows the Cray 2 with multiple 4 Gbit paths to I/O (think PCIe
x ~2).

~~~
dm2
This table indicates that PCIe v2 is 4 Gbit/s per lane (64 Gbit/s for 16
lanes) and PCIe v4 is almost 16 Gbit/s per lane (up to 252 Gbit/s total). Is
this correct or am I misunderstanding what you are saying?

[http://en.wikipedia.org/wiki/PCI_Express#History_and_revisio...](http://en.wikipedia.org/wiki/PCI_Express#History_and_revisions)

~~~
ChuckMcM
I was thinking PCI Express, Version 1, by 2 lanes. There are four of those if
I read correctly which would be essentially 8 lanes of ver1 PCIe.

Rather a bit more I/O bandwidth than your iPhone has, but not as much as say a
current desktop.

~~~
dm2
Here is an interesting page:
[http://en.wikipedia.org/wiki/List_of_device_bandwidths](http://en.wikipedia.org/wiki/List_of_device_bandwidths)

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waskosky
"Whistlebower" Dr. Bill Deagle, MD claimed that the unique Gallium Arsenide
chip technology that was being worked on by the Cray Computer Corporation
essentially became classified by the US Air Force, and that it was developed
much further than is publicly known, and that he witnessed a "Cray 5"
computing array in operation.
[https://youtu.be/tOz0-Hy1rm8?t=462](https://youtu.be/tOz0-Hy1rm8?t=462)
(7:41)

When you compare the properties of Gallium Arsenide to Silicon chips, it makes
a lot of sense that the military would be highly interested.
[http://en.wikipedia.org/wiki/Gallium_arsenide#Comparison_wit...](http://en.wikipedia.org/wiki/Gallium_arsenide#Comparison_with_silicon)

~~~
Animats
That guy is bogus. There have been some real cryogenic computing devices,
though. IBM and NSA put huge efforts into that back in the 1950s. ("I want a
thousand megacycle computer. I'll get you the money" \- NSA director).[1] The
first generation technology, cyrotrons, sort of worked, but mainstream
technologies pulled ahead, and that technology was abandoned in 1965. IBM kept
plugging away at cyrogenic computing through the 1980s, with Josephson
junctions being the next technology. Those run at liquid helium temperatures.
With great difficulty and at huge cost, they got some experimental electronics
(not a full CPU) running at 300MHz. By this time, it was 1982, and while that
was about 10x faster than the fastest microprocessors of the period, it looked
like the upper limit of the technology was around 1GHz. That, plus high cost,
plus all the headaches of working in liquid helium, indicated the Josephson
junction was a dead end. Standard CMOS was going to outperform the exotic
technology. So, in 1983, IBM pulled the plug on that project.

They're trying again.[2] IBM is working on superconducting quantum computing,
and has been busy since 2012. Maybe this time it will be useful. It will
definitely be expensive.

[1]
[http://www.ewh.ieee.org/tc/csc/europe/newsforum/pdf/RN28-1.p...](http://www.ewh.ieee.org/tc/csc/europe/newsforum/pdf/RN28-1.pdf)
[2] [http://defensesystems.com/Articles/2014/12/04/IARPA-
cryogeni...](http://defensesystems.com/Articles/2014/12/04/IARPA-cryogenic-
exascale-supercomputing.aspx)

------
userbinator
To put the specs in more modern terms, it's roughly a 64-bit quadcore with 2GB
of RAM and a clock speed around 250MHz. Enormously powerful for 1985, but
probably slower than a typical desktop system in 2005.

No mention of secondary storage... but with 2GB of RAM, maybe it didn't need
any?

~~~
ChuckMcM
Disk channels to SMD or SCSI disk subsystems (maybe IPI but those disks were
temperamental at best).

As I recall it wasn't until SSE3 instructions which were in the mid-2000's
that an x86-64 desktop could compute an image convolution in the same time it
took the Cray 2 but I'd have to ask Ram Nevatia. He was always finding the
fastest way to do various image analysis programs.

------
Animats
A few years ago, somebody got a Cray 2, barrels of Fluorinert and all, and was
going to restore it. Whatever happened to that? Probably not much.

Restoring old computers is a huge task. The Computer Museum in Mountain View
worked for years to restore an IBM 1401, a small mass-produced machine from
the 1960s. They had techs who'd worked on them and access to the original
designers, and it was still very hard.

~~~
CamperBob2
The biggest challenge may be powering it up. The brochure says it sucks down
300 kW. I'm guessing it'll need a 440V polyphase feed to run the 400 Hz motor
generators...

~~~
kjs3
Yeah...the Cray 2 basically required it's own power substation be installed.

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tiernano
I started to read this and remember seeing [this][1] from a couple of years
back... with the liquid cooling, etc, i would love a replica of the 2...

[1]: [http://www.extremetech.com/extreme/191877-how-to-build-
your-...](http://www.extremetech.com/extreme/191877-how-to-build-your-
own-110-scale-cray-1-supercomputer)

------
trimbo
Ah, heady days when the world's best computers were made in Chippewa Falls,
Wisconsin and _featured waterfalls of Fluorinert_ for cooling.

By the time I saw a Cray-2 in person, it was shut down (it was so outmoded it
was not worth running). But an awesome sight.

~~~
germinalphrase
As a Wisconsin native, that Cray was situated in Chippewa Falls was always a
fun piece of tech trivia.

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gefh
So 2GB of memory, 4 cores at ~250Mhz (was the foreground processor the same?
Brochure seemed unclear), runs a *nix. About 15 years ahead of a late 90's
Pentium I guess, but more ram. Just need the spare 16 square feet of floor
space.

~~~
tiernano
and 300KW of power to run it!

~~~
jwr
And don't forget that you also have to get rid of 300kW of heat. Having worked
in a supercomputing center, this is a major problem — think about how quickly
you have to shut your computers down if your heat exchanger goes down, before
the room gets too hot to enter.

~~~
frozenport
Roomer has it that the original Cray 1 design didn't have a tunable cooling
unit. One day the test machine crashed, and the engineers came in the next
morning to see a giant icy glacier.

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jdalgetty
Yes, but can it run Crysis?

