18 (Материалы к экзамену)

Newsgroups: comp.parallel,comp.sys.super

From: eugene@sally.nas.nasa.gov (Eugene N. Miya)

Reply-To: eugene@george.arc.nasa.gov (Eugene N. Miya)

Subject: [l/m 2/27/98] What *IS* a super? comp.par/comp.sys.super (18/28) FAQ

Organization: NASA Ames Research Center, Moffett Field, CA

Date: 18 Mar 1998 13:03:14 GMT

Message-ID: <6eogmi$ok$1@cnn.nas.nasa.gov>

Archive-Name: superpar-faq

Last-modified: 29 Jan 1998

18Supercomputing and Crayisms

20IBM and Amdahl

22Grand challenges and HPCC

24Suggested (required) readings

26Dead computer architecture society

28Dedications

2Introduction and Table of Contents and justification

4Comp.parallel news group history

6parlib

8comp.parallel group dynamics

10Related news groups, archives and references

12

14

16

Not heard in these parts:

This computer is good for {select one: 51%, 90% 99%}

of your needs.

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

-------------

0) A Japanese company. ;-)

1) "My definition is 'best,'

"A Supercomputer is the one that runs your problem(s) the fastest.""

2) "A supercomputer is a device for converting a CPU-bound problem

into an I/O bound problem." [Ken Batcher]

3) "A supercomputer is one that is only one generation behind what

you really need." Neil Lincoln's definition.

3a) "Hardware above and beyond, software behind and below"

3b) A machine to solve yesterday's problems at today's speeds.

4) Page _one_ of the Linpack-report...

What is Linpack? (LINPACK)

----------------

Linpack100x100 - All Fortran, dominated by daxpy unless advanced compiler

optimizations are available. Seldom quoted in marketing literature

because the performance is much lower than the following two.

However, Dongarra sorts his chart by machine performance on this benchmark.

Linpack1000x1000 - Typically Vendor Library routines which use BLAS3 or

LAPACK routines (N**2 data refs for N**3 operations)

Shows single processors with high floating point capacity in favorable

light, so often quoted in marketing literature.

Linpack NxN - problem size determined by Vendor, good for parallel machines

since with correct choice of problem size can maximize the computation

per communication step. Often quoted in marketing literature for

the larger parallel systems.

"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."

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."

"You can't fake what you don't have".

"Can't use what you ain't got!"

"In this business, you can't fake what you don't have"

[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 died.

Apple is only using their EL as a file server.

We have also covered the parity quote (panel 10).

1) Mr. Cray had always worked with core (yes Virginia, little ferrite

toruses with wires hand threaded through them). Core memory was rock stable

& almost *never* failed. My RCA 70/45 crashed 3 times in 4 years with

memory parity errors and one of those crashes was due to a friend hitting

the A/C Power Emercency Off button on the console!

2) When he designed the first Cray-1, s/n-1, Mr. Cray used RAM chips with

straight parity. The system was installed at the Los Alamos National

Laboratory. It averaged 20 minutes of blinding speed per system failure

(due to a parity error in memory). This was obviously a problem, so, after

consulting with the LANL folks ...

3) Development was halted on s/n-2. The next machine, s/n-3, was designed

with Single Error Correction - Double Error Detection (SECDED) parity in

it's memory. This machine was sold to the National Center for Atmospheric

Research (NCAR) where it ran (with very few double-bit error crashes) for

many years. An aside here is that NCAR had the absolute audacity to

require that an Operating System come with the system, so Cray hired a

(shudder) programmer to write one!

4) Note that this is memory! The Cray-1 line had SECDED memory. No parity

checking was done in the CPU. The same was done for the X-MP. The Y-MP

extended parity checking to the CPU. ...

Cray and new ideas (non-cray)

-----------------------------

The story frequently goes:

A bright student or architect somehow manages to get time to visit

Seymour. Cray will listen to that student's ideas and nod understanding

or disagreement. He listens to a few ideas, but he makes a comment like

"Sounds good."