[l/m 2/27/96] What *IS* a super? comp.par/comp.sys.super (18/28) FAQ
Eugene N. Miya
18 Supercomputing and Crayisms
20 IBM and Amdahl
22 Grand challenges and HPCC
24
26
28 Dedications
2 Introduction and Table of Contents and justification
4 Comp.parallel news group history
6 parlib
8 comp.parallel group dynamics
10 Related news groups, archives and references
12
14
16
What's constitutes a supercomputer?
-----------------------------------
What makes a supercomputer?
===========================
The fastest, most powerful machine to solve a problem today.
Generally credited to Sid Fernbach and George Michael and others
What if I qualify that with "cost?" ["for the cheapest"]
--------------------------------------------------------
Then, it's not a supercomputer. Period.
It might be a minisupercomputer, though.
Don't let George know that I said that (he's much more hardline).
Other answers
-------------
A Japanese company. ;-)
1) "A supercomputer is a device for converting a CPU-bound problem
into an I/O bound problem." [Sometimes credited to Ken Batcher and others.]
2) "Hardware above and beyond, software behind and below"
A machine to solve yesterday's problems at today's speeds.
"A supercomputer is a machine which costs between $7M and $20M.
[~1984 prices].
[Today, I guess you could change the range to $10M-$30M or so (how much is a
full-up T-90 go for at the usual discount?]
For some strange and mysterious reason, this really used
to bug people who wanted to believe that "supercomputers"
had a kind of magical, mystical aura. For some reason,
the same folks would get mad when, by the numbers, their
PC's were about ~1/1,000,000 of the then-current Cray & CDC -
they also wanted to "believe in" their PCs. My puzzlement
over this double denial is probably why I am not a successful politician.
--Hugh LeMaster
See also Grand Challenges panel.
----------------------
Where do the terms minisupercomputer and Crayette come from?
============================================================
Convex Computer Corp. coined the term minisupercomputer and that
has largely stuck even though they consider themselves now a full fledged
super computer company. "Crayette" came from Datamation for SCS,
because SCS had an Cray/COS object code compatible X-MP machine at
a fraction of the cost/performance.
Crayisms
========
The news group has covered a variety of Crayisms or sayings (some are
apoc.*ful).
%A Russell Mitchell
%T The Genius: Meet Seymour Cray, Father of the Supercomputer
%J Business Week
%N 3157
%D April 30, 1990
%P 80-86
%K Cover story, biography, circular slide rule, Cray-3,
%X Text of this article is available via Dialog(R) from McGraw-Hill
0210276
Some of these are Rollwagon-isms.
On Schedules and bureaucracy:
"Five Year Goal: Build the biggest computer in the world.
One Year Goal: Achieve one-fifth of the above."
We have also covered the parity quote.
On 2s-complement arithmetic.
'Although many "Seymour stories" are based in fact,
most are wildy exaggerated:'
On digging holes (tunnels): a 12-foot hole for wind surfing gear.
On burning boats (Rollwagen: made up the party and Carolyn Cray Bain:
"it was the easiest way to get rid of a boat").
Virtual Memory (compared with sex).
"Memory is like an orgasm - it's better when you don't have to fake it."
[Gee, I guess this quote makes this FAQ R-rated.]
On wood paneling.
I hear Seymour Cray designs machines on his Apple MacIntosh.
And that Apple designs MacIntoshes on their Cray.
%A Marcelo A. Gumucio
%T CRI Corporate Report
%J Cray User Group 1988 Spring Proceedings
%C Minneapolis, MN
%D 1988
%P 23-28
%K 21st Meeting
%X Seymour has 6 Apple Macs (Macintosh) used to design Crays (not just one).
Q&A section.
[Gordon Bell {See the IBM panel} admits he designs his computers on Macs, too.]
Alas, this is getting old. Seymour is reaching retirement, and
Apple is considering costs to remove their Cray. It might be gone
if you are reading this.
He is an expert on cooling and refrigeration technology.
A survey article by Saul Rosen in the first issue of _ACM
Computing Surveys_ mentioned that the original core memory on the
IBM-7090 (1958?) was oil-cooled, although it was quickly replaced
by an air cooled version. As the 7090 used much of the memory
technology from the 7030 Stretch, does this mean that the Stretch
memory was oil-cooled?
The IBM7030, 7090, 1401(early models) all had memories cooled by immersion in
oil. The same is true for the Harvest - ask Norm Hardy about this.
The SAGE machine produced by IBM was the (FS) Q32. It was water cooled.
I remember seeing this machine at SDC in Santa Monica.
"The future is seldom the same as the past" - Seymour Cray, 6/4/95.
Many people claim to have a Cray-1 (on a chip, on a board, for 1/100 the price,
-------------------------------------------------------------------------------
etc.). What does this mean?
----------------------------
Almost nothing.
The Cray-1 is an early circa 1970s:
A distinguished machine for its time, but you might also consider
comparing the ENIAC.
The Cray-1's lessons include vector registers and instructions,
the importance of fast, simple scalar processing (frequently forgotten).
Considering an element-wise break down of the basic features meant:
Processor speed, memory size, I/O bandwidth:
12.5 ns clock cycle (a few machines have this).
Most instructions executed in one cycle (contributing to
RISC ideas).
about 1 or less Megaword or memory, that's about 8 MBs (the amount
of memory in my Apple PowerBook[tm]). Yep, Cray-1 performance.
This capacity over-simplifies the architecture's multibanked
memory.
fast I/O: 13.3 MB/S I/O point-to-point wiring,
disk striping (IOS required), etc.
features not usually found on micros.
The original Cray-1 cost $8.6M. It was sold for $8.8M to NCAR.
This is all a gross generalization/simplification.
Don't compare modern machines to obsolete machines;
if you do that, then compare against the ENIAC like Alan Perlis did
(next section).
How do I get a (used) Cray-1?
=============================
The group is tired of hearing Cray-1 comparisons. The Cray-1 was a fine
machine for its time, but the rest of us have moved ahead.
You might as well be talking about the ENIAC
(in fact Alan Perlis in his Epigrams did:
"Just think with VLSI we can have 100 Eniacs on a chip.")
The same goes with the TMC Connection Machine CM-1.
What is the time line for
-------------------------
ERA (Engineering Research Associates)
Univac
CDC (Control Data Corporation)
| -----> ETA (Engineering Technology Associates)
Cray Research Inc.
| Acquires:
| Supertek
| Celerity
| Floating Point Systems
Supercomputer Systems Inc. (SSI [1 of 2]) [S. Chen]
Now off doing Pentium based mass storage servers
Cray Computer Corp.
asserts being liquidated
March 24, 1995
To Our Employees:
I am sorry to tell you our company has run out of money. We have nearly
run out of money so many times before that it is shocking now that it
has really happened. We have been trying to raise 20 million dollars to
carry the company through the rest of the year and bring the Cray-4 to the
marketplace. I believe we chose the best opportunity to raise that money,
but it has not been successful. We must therefore close our operation and
deal with the debts which we owe.
I am very disappointed, as I am sure you are. We have spent six years of
our lives developing a technology which seemed like an important contribution
to science. To not complete such a long effort is very disheartening.
I have asked myself if there were mistakes made, which if done differently,
would have allowed us to complete the project. I do not believe so. I
think the goals were right, and I think we did the very best we could to
accomplish those goals.
Our problem is basically one of timing. The business world, and our
government, are in a cost cutting mode. They do not wish to take any risks
at the moment. Long term investment for the future is not popular.
Many people think there are already too many computers. In a different
decade we would probably have succeeded. So in the sense that we did our
best I cannot feel bad.
I have enjoyed working with each of you and will miss this relationship
very much. Somehow we each have to go home and think about how we get
on with the rest of our lives. I am sure this will not be easy for any
of us. I wish you each well, and thank you for being a part of my life
for the years we have had together.
(signed) Seymour
What's "better" 'long-vector' or 'short-vector?'
------------------------------------------------
Are vector register computer parallel computers?
================================================
This is an older question from net.arch/comp.arch.
It depends on whether you believe pipelining is a form of
"temporal parallelism."
'Long-vector' machines: TI ASC, CDC 203/205, ETA-10[EGQP]
'Short-vector' machines: Cray, Convex, Alliant, Weitek based chip set
A highly application dependent question.
I theorized (guessed) in the late 1980s that short vector machines
succeeded because as algorithms transitioned from 2-D code to 3-D codes,
the additional dimension took up the memory organization rather than the
lengthing of any single dimension.
This is clearly a gross generalization, because many communities did
retain the use of long-vectors.
See also other key words: "strip mining."
The spooks asked for and got an instruction to do "population counts"
---------------------------------------------------------------------
(the number of bits per word).
==============================
This is a common note/story. You tell us. 8^)
Why .h files?
=============
The name space.
It is important to establish a foothold in the name space.
The collision problem is becoming worse.
A company with a name like Cray (say) publishes *.h files in the public
domain using #defines on certain 8 characters sequences. A few non-Cray
software designers in writing tools use #ifdef CRAYs to inflate their egos
(it happens), learn bug reports from people using real Crays,
meanwhile the name space develops some interesting collisions.
Then more software tools appear on your architectures, some of which aren't
bad tools. Keep your tools proprietary, tool development takes longer.
It works, you are reading this on the Usenet, right?
This is why letting the world know your source code is important.
"If it isn't source, it isn't software."
--Dave Tweten "Datamation"
What's "class 6?" (class VI)
============================
The US Dept. of Energy developed a scale of ranking their supercomputer
purchases.
If someone tells you, "XXX is a class 7 machine" or a class 8 or
higher number machine:
they don't know what they are talking about.
If you think I am trolling, you are right. I want someone to PROVE to
me that a DOE Class VII designation really exists (i.e., not merely
mentioned by someone in a paper).
Ref:
%A Sidney Fernbach, ed.
%T Supercomputers, Class VI Systems, Hardware and Software
%I North-Holland
%C Amsterdam
%D 1986
%O ISBN 0-444-87981 1
%K book, text, cray, cdc cyber, data flow, NEC SX-2, Fujitsu VP-200,
Hitachi 810/20, vector processing,
%X A collection of papers surveying existing computer architectures
rather than newer proposed supercomputer architectures.
%X A book from one of the men who set up the "Class system" of the DOE.
What's my VAX/IBM PC on these scales?
=====================================
"Class 1/2." -- Sid Fernbach.
No, in simple terms, they don't rate to be placed on the scale.
It is normalized for the specific time period asked.
"These aren't real computers; they are marijuana." -- George Michael
But this is silly, the PC is more powerful than the Eniac.
----------------------------------------------------------
So build a time machine and send a VAX/PC back in time and you will have
the most powerful computer in 1946.
What is the influence of the CDC 6600 and Seymour Cray on RISC Architectures?
=============================================================================
Cray is widely credited as influencing (inspiring)
Hennessy, Patterson, Cocke, Tredennick in their initial designs.
The issue is not simply one of raw performance. The issues involve
design development time and reaching market.
%A J. E. Thornton
%T Design of a Computer: The CDC 6600
%I Scott, Foresman & Co.
%C Glenview, IL
%D 1970
%K recommended,
%K btartar
%X The 6600 has influenced a lot of the supercomputers from
Cray and CDC. Also no commercial manufacturer of such
an outstanding machine has ever revealed so much detail.
Amos Omondi
Look up references on the IBM 801, SOAR, MIPS.
How many instructions were in the CDC instruction set?
======================================================
Ask Horst Simon 8^).
What constitutes 'balance?'
===========================
An interesting vague question.
A useful analogy comes from the icon of the Salishan Conference
(remember that from another panel?):
^ A
s / \ r
m / \ c
h / \ h
t / \ i
i / \ t
r / \ e
o / \ c
g / \ t
l / \ u
A / \ r
<_____________________> e
Language
I might take issue with aspects of this model, but it's more useful to
consider other ideas based on it:
^
/.\
e / . \ S
r / . \ o
a / . \ f
w / . \ t
d / . \ w
r / . \ a
a / . . \ r
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<_____________________>
Algorithms
^
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<_________________________________________>
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<_________________________________________>
A p p l i c a t i o n
I prefer the reduction.
George has gone three-dimensional. I have a 3-D model (since I used
to work with sheet metal).
Where are the supercomputers?
=============================
Two separate lists are compiled. Their existence is periodically posted.
The reader must realize the competitive and secretive nature of some
of this market, politics, and commerce. All such lists must be regarded with
some suspicion. Manufacturers have their ax (keep customers), users (like
big industrial or government concerns) have their ax, etc. Any list is
suspect. Lists like these and announcements could also be used for
disinformation. See "Why is this group so quiet?"
So don't expect reliable stats without first signing a non-disclosure
agreement.
http://www.mordor.com/gunter
gun...@ritz.mordor.com (Gunter Ahrendt)
Then there is the German list.
http://parallel.rz.uni-mannheim.de/top500/top500.html
I would be willing to make my WWW list of supercomputing
and parallel sites into an official comp.parallel/
comp.sys.super page, still maintained by me.
http://www.umiacs.umd.edu/~dbader/sites.html
Currently, on a slow week, this page gets about 600-1000 accesses.
WWW List of Parallel & Supercomputing Sites and Vendors
-------------------------------------------------------
http://www.umiacs.umd.edu/~dbader/sites.html
This WWW page is updated regularly and features
links to World-Wide Parallel & Supercomputing
*-* Research Sites (Academic, Government, and International)
*-* Vendors
*-* Related supercomputing information
There is a quick-index to the Sites, as well as a
reverse-chronological listing of new updates.
Date: Wed, 15 Mar 1995 09:26:56 -0700
From: Jim Davies <jr...@Craycos.COM>
Message-Id: <1995031516...@tnt.Craycos.COM>
Subject: Re: cray
>|We have a Cray-2 prototype here called snq2 (q for quadrant),
>snq2 isn't the thing that Newt Perdue had a photo of in the aquarium?
I don't really know; I've only worked here, not at CRI. I think
there was a snq1 also, which would have been the first prototype.
>S7? Not a serial number is it?
Sort of; it's the "seventh" Cray-3 tank we built. Numbers S1 through S4
are one-octant tanks, S5 and S6 are two-octant tanks (S5 is the one
at NCAR which they call "greywolf"), and S7 is the only four-octant tank.
The module sets have tended to roam freely between tanks as needed
(e.g. S6 hasn't ever spent any long periods in production because it
gets used to test spare and replacement modules for S5 and S7).
S4 has been converted to a 2-octant tank for use as the PIM system.
S1 through S3 are essentially gone at this point -- replaced by Cray-4
tanks.
Yes. They're not quite like the old T registers, in that they have
data paths to the A, S, and V regs. We're using them for argument
passing, stack pointers, scalar register spills, scratch space for
vector reductions, etc. (i.e. the same sort of things local memory
was used for, except no vector register spills). There are no direct
move instructions between A and S registers, so they're used for
those moves also (and we still have a word-addressable architecture
so we need to do character pointer manipulation in S registers,
shifting and masking to convert char pointers to word pointers, etc.).
My feeling about local memory was that it was never large enough.
In fact, Seymour's initial Cray-4 design had a larger local memory
(128K or 256K, one or two extra modules depending on user's needs).
He was convinced by our benchmarkers that an extra memory port would
be more useful, in addition to reducing the processors to one module apiece.
It seemed logical, since the goal of caching is to ease the memory
bottleneck, and the second memory port also helps with this (while
making the machine smaller).
Arguably one of our problems with local memory was lack of adequate
compiler technology to use it; to properly use it as a programmable cache
really requires looking at entire loop nests rather than the cray-traditional
inner-loop-only vectorization scheme. We're working on loop-nest optimizations
now, since even the vector registers may be used this way in many cases.
Also, which port gets used for a particular load or store is completely
under the programmer's control, so the compilers have to make some tougher
optimization choices in this regard also.
>Every one else wants CCC to do well. I suggested to a friend at IBM TJW to
>again submit a PR to get a C-4.
Thank you. Our problem, as always, is making the machine work. It's
always seemed that once we can produce a reliable fast system the
marketting should be the easy part (although the Cray-3 was so late
that it wasn't true for that machine).
Take care,
-- Jim