Path: utzoo!mnetor!tmsoft!torsqnt!news-server.csri.toronto.edu!cs.utexas.edu!swrinde!zaphod.mps.ohio-state.edu!sol.ctr.columbia.edu!emory!hubcap!john%ghostwheel.unm.edu
From: john%ghostwheel.unm.edu@ariel.unm.edu (John Prentice)
Newsgroups: comp.parallel
Subject: Re: Justifications for || processing
Message-ID: <12324@hubcap.clemson.edu>
Date: 18 Dec 90 13:52:40 GMT
References: <12301@hubcap.clemson.edu>
Sender: fpst@hubcap.clemson.edu
Organization: Amparo Corporation, Albuquerque, NM, USA
Lines: 30
Approved: parallel@hubcap.clemson.edu

In article <12301@hubcap.clemson.edu> pur-ee!muttiah@stable.ecn.purdue.edu (Ranjan S Muttiah) writes:
>I'm wondering how people in the application side of parallel processing
>justify coding for a parallel machine.  I would be very much interested
>in knowing how much complexity analysis plays a part in this.
>

My group here justifies it simply on the basis of the fact that we can't
get the performance we need for our calculations without it.  We are doing
computational solid dynamics and Monte Carlo quantum scattering calculations.
We want to be able to do 3 dimensional calculations, but the current machines
aren't up to it.  Parallel systems offer a hope as we get systems that
can do 100 Gigaflops and up.  We don't see serial systems (vector, etc...)
as the route to this kind of performance.  Neither does anyone else so
far as I have heard (consider that even Cray is now getting on the parallel
bandwagon).

As far as complexity analysis, it is not used in our efforts.

>On a related note, how prevalent are compilers that parallelize code ?

I don't know of any in the applications world.  On the CM2, the Fortran compiler
detects parallelism by the use of Fortran Extended array syntax which
is somewhat "automatic" I suppose (except that you have to put in this
syntax specifically for the CM2, nobody else uses it.  When Fortran Extended
gets out, that will be another matter).

John K. Prentice
Computational Physics Groups
Amparo Corporation
Albuquerque, NM  USA