Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!uwm.edu!lll-winken!vette!brooks
From: brooks@vette.llnl.gov (Eugene Brooks)
Newsgroups: comp.arch
Subject: Re: ATTACK OF KILLER MICROS
Message-ID: <36593@lll-winken.LLNL.GOV>
Date: 23 Oct 89 16:24:02 GMT
References: <35825@lll-winken.LLNL.GOV> <2121@brazos.Rice.edu> <35897@lll-winken.LLNL.GOV> <9078@batcomputer.tn.cornell.edu> <36232@lll-winken.LLNL.GOV> <9119@batcomputer.tn.cornell.edu>
Sender: usenet@lll-winken.LLNL.GOV
Reply-To: brooks@maddog.llnl.gov (Eugene Brooks)
Organization: Lawrence Livermore National Laboratory
Lines: 34

In article <9119@batcomputer.tn.cornell.edu> kahn@batcomputer.tn.cornell.edu (Shahin Kahn) writes:
>If you have scalar dominated code that fits in a workstation's memory
One should not attempt to infer that a workstation's memory is small.
An YMP 8/32 has 4 megawords (32 MB) available per processor.  If all you
want is 32 MB per processor you can buy this with a killer micro for
about 40K, simply throw it away in a year when its performance has been
eclipsed by the next killer micro, and still have your computer time work
out to be about 5 dollars an hour.  They have the gall to charge $250 an
hour for Cray YMP time, for low priority time at that.
>THAT, is significantly faster than a single processor XMP.
>
>REWRITE the code!!  Or have someone do it for you (there was a company
>that would get your code to run at least twice faster or your money back,
>I forget the name and dont know them or anyone who does).  
We did!  And we showed that you could asymtotically get the factor of 2
you suggest with infinite work.  Why suggest doing such a thing when
one can get a factor of 100 with little work on 100 killer micros?

>If they dont perform,
>Throw away all the dusty decks.  Refuse to use dusty-deck oriented code.
This was not a dusty deck.  This code was written in the last couple of
years with modern tooling, for both vectorized and MIMD parallel machines.
It is not the code which is scalar, it is the algorithm.  One could say
toss out the algorithm, but it is one most robust ones available for the
application in question.


>A 256 MB micro can cost you some.  And not so little.
But it is much cheaper than a SUPERCOMPUTER for my application,
and it is FASTER.  To bring back the car analogy, the accelerator
is still pressed to the metal for speed improvements in killer micros.


brooks@maddog.llnl.gov, brooks@maddog.uucp