Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ames!killer!texbell!bellcore!dduck!johno
From: johno@dduck.ctt.bellcore.com (John OBrien)
Newsgroups: comp.sys.sequent
Subject: Re: Questions about Pyramid/Sequent
Message-ID: <15106@bellcore.bellcore.com>
Date: 3 Apr 89 17:28:52 GMT
References: <764@sactoh0.UUCP> <63900002@uxf.cso.uiuc.edu>
Sender: news@bellcore.bellcore.com
Reply-To: johno@dduck.UUCP (John OBrien)
Organization: Bellcore (The Joe Irby Bar and Grill)
Lines: 27



	This has been a great discussion and it's good to see it
hasn't degenerated into vendor bashing.  Here's my perspective on the
fast single processor vs. several "smaller" processors.  This is not
an endorsement for or against either vendor (can't do that if I want
to keep my job).  I've worked on both for quite some time with most of
the work concentrating on the issues of multi-processor vs single processor.

	It is interesting to note that that vendors such as Pyramid
(among others) have gone from uni-processor systems to multi-processor
systems (Pyramid's 98xx series, DEC's 6000 series, etc) for various
reasons (most of which are economic).  So whether people like it or
not, that is the way of the world.

Several people have talked about the advantage of one fast processor for
number crunching applications.  However, that advantage disappears
with the addition of just one more user.  Simplistically, your single
user CPU power is reduced by 50% with the addition of the second
user.  In a multi-processor environoment, it more users for the system
to lose that amount of power.

In reality, the capabilities of a multi-processor architecture are
limited by the ability of the operating system and architecture
to efficiently handle the processors and the interactions between them.

John O'B