Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!mcsun!ukc!mucs!mshute
From: mshute@cs.man.ac.uk (Malcolm Shute)
Newsgroups: comp.arch
Subject: Re: Historical architectural advances??
Message-ID: <1888@m1.cs.man.ac.uk>
Date: 6 Nov 90 12:30:24 GMT
References: <8185@scolex.sco.COM> <1868@m1.cs.man.ac.uk> <8553@scolex.sco.COM>
Sender: news@cs.man.ac.uk
Reply-To: mshute@cs.man.ac.uk (Malcolm Shute)
Organization: Department of Computer Science, University of Manchester UK
Lines: 34

In article <8553@scolex.sco.COM> seanf (Sean Fagan) writes:
>In article <1868@m1.cs.man.ac.uk> mshute@cs.man.ac.uk (Malcolm Shute) writes:
>>Does your classification scheme handle a loosley coupled system
>>(such as a department's worth of SUNs connected on a LAN)...
>>Does the overall system (network) qualify as being a mainframe/supermini?
>Do you, your wife, and your two children qualify as a single person with 8
>arms?  No.

Not so fast with your glib remarks!
I asked the question expecting you to say "No", but I was interested in
the logic behind your classification.
I, my wife, and two children (if indeed I were married and had two
children) would have different DNA, so you would be able to distinguish
the 4.0e12 (or whatever) cells of our four combined bodies into
four distinct organisms;  you would have a harder job with four
*interconnected* computers.

What is the difference between a loosely coupled multicomputer system,
and a tightly coupled multiprocessor computer?

Granularity of processes for scheduling, and geography of the 'cabinet'
size.  That is all (just about).

Our LAN fits into a cabinet called the Department of Computer Science.
How much smaller would it have to be before you would consider it to
be a single multiprocesser computer?  Or, what other criterion would
have to be met before it crossed the threshold?

I am seriously interested in finding out how people in  comp.arch  make
this distinction.  Is it possible that there is *no* firm dividing line
between the two?  Does it matter to have an answer to the question?
--

Malcolm SHUTE.         (The AM Mollusc:   v_@_ )        Disclaimer: all