Hello SUN managers:
******************************************************************
My original posting:
Can one get any speed gain from the dual-CPU config on a single
*ordinary* job? I.e., assuming no attempt has been made by a
programmer to write a parallel program, and you run just one single
job, does the system automatically do any low-level parallelizing
to speed up your single job? If so, what kind of speed gain could
one reasonably hope to get? (I realize that any speed gain would
be highly dependent on the nature of the job, but just want a rough
idea.)
*****************************************************************
My summary:
Thanks for all those replied! The majority said there is NO gain
unless:
. you use parallelizing compiler such as SUN's Impact.
. use some parallel virtual machine (e.g. PVM). This will
allow your source to be modified to treat each processor as
a distributed node.
. the program does some forking, or spawning of other jobs.
Many thanks to:
Bert N. Shure
Michael R. Zika
Matthew Stier
Rich Kulawiec
Kai O'Yang
James H. McG. Sibl
Greg Price
Peter Bestel
Kevin Sheehan
Alex Finkel
Marc S. Gibian
Jay Lessert
*****************************************************************
Details of the responses:
From: "Bert Shure" <bert@virtual.com>
no luck unless the application is written to take advantage of multiple
cpu's.
the only winning aspect of the two processor system is that one
processor could use all the memory if nothing else is happening on the
system.
-------------------------------------------------------------------
From: "Michael R. Zika" <zika@oconto.tamu.edu>
No.
None.
If you're looking at a parallel applications, I would recommend one of
the following:
o Purchase the iMPact toolkit with the SunSoft compilers. This will
let you code shared-memory parallel directives into your code.
I've used these and had good success with some small real world
applications. It also provides and auto parallelization option.
o Install PVM (Parallel Virtual Machine) or MPI (Message Passing
Interface). This will allow your source to be modified to treat
each processor as a distributed node. This allows you to treat
your shared memory machine as a distributed memory machine (if
that's what you want)
In both cases, source code modifications will be required.
-------------------------------------------------------------------
From: "Matthew Stier" <mstier@hotmail.com>
1) There never is just 'one' job running on a computer.
2) If the program does any forking, or spawning of other jobs, you can expect
some improvement.
3) You don't necessarily need multi-threading, to get a performance boost from
a multi-processor computer.
-----------------------From sun-managers-relay@ra.mcs.anl.gov Thu Mar 13 06:28:41 1997
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From: "Scott Williamson" <scottw@morse.co.uk>
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Subject: SUMMARY: Boot Prom version
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Thanks to all who wrote.
"prtconf -V" shows Open Boot Prom revision, which is not quite what
I wanted. Got a value of "OBP 3.1.1 1996/03/08 14:20" on my system.
Stop-A on the console, followed by "banner" then "go" to resume gives
the ROM revision, 2.28, which is what I was really after. Maybe I
didn't ask the correct question.
This is the value which, for example, has to be at least 2.25 to be
able to use Ross HyperSPARC modules in a SPARC 20.
Other people mentioned the "sysinfo" package as something which might
give this information. It would be nice to think that there's some
way of getting it without hanging the system.
--Scott Williamson Morse Computers Tel.: 0131 226 3300 Senior Consultant 60 Melville Street Direct: 0131 260 3314 mailto:scottw@morse.co.uk Edinburgh Fax: 0131 226 3535 http://www.morse.co.uk EH3 7HF Mobile: 0370 865370
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