Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!wuarchive!emory!hubcap!john%ghostwheel.unm.edu
From: john%ghostwheel.unm.edu@ariel.unm.edu (John Prentice)
Newsgroups: comp.parallel
Subject: Re: How much are you willing sacrifice.
Message-ID: <12998@hubcap.clemson.edu>
Date: 7 Feb 91 23:16:02 GMT
References: <12935@hubcap.clemson.edu> <12971@hubcap.clemson.edu>
Sender: fpst@hubcap.clemson.edu
Organization: University of New Mexico, Albuquerque, NM
Lines: 44
Approved: parallel@hubcap.clemson.edu

[Editted for length.]


In article <12971@hubcap.clemson.edu> think!barmar@think.com (Barry Margolin) writes:
>In article <12935@hubcap.clemson.edu> "PBACAD::M_PAPRZYCKI"@UTPB.PB.UTEXAS.EDU writes:
>>   The first point I would make is that `efficiency' is very much less
>>   important to me than coding clarity. I am quite prepared to sacrifice
>>   half my CPU time if it makes the code easier to maintain. 
>
>How about: "I could have run your program in 3 hours,....so it requires 6
>hours."  Program clarity is not just an esthetic quality, it directly
>affects programmer productivity.

I would tend to think this question of balancing speed against clarity
is a rather obvious one.  Common sense tells you pretty much whether you
need speed at the expense of clarity, etc...  What is there to argue about?
For the applications we work on for example, our serial codes take hundreds
of hours of Cray Y-MP time for each calculation.  It is well worth our
time to convert them.  We have other codes that take hours of Cray time,
but it is not worth it to us to convert them to parallel systems because
that takes time and these codes aren't worth it in terms of their cost
to run. Our experience has been, if you need speed bad enough to consider
porting to ANY supercomputer (and in particular parallel ones), you know
about it!  The choice is obvious in such cases.  

John
--
John K. Prentice    john@unmfys.unm.edu (Internet)
Dept. of Physics and Astronomy, University of New Mexico, Albuquerque, NM, USA
Computational Physics Group, Amparo Corporation, Albuquerque, NM, USA