Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!uupsi!TALOS!jerry
From: jerry@talos.npri.com (Jerry Gitomer)
Newsgroups: comp.arch
Subject: Re: Amdahl's Rule
Message-ID: <2285@talos.npri.com>
Date: 21 May 91 13:32:26 GMT
References: <48qO01yL75GS00@amdahl.uts.amdahl.com> <1991May19.025126.24526@netcom.COM>
Distribution: world
Organization: NPRI, Alexandria VA
Lines: 31

wigen@netcom.COM (Patrick L. Wigen) writes:

:In article <48qO01yL75GS00@amdahl.uts.amdahl.com: terry@uts.amdahl.com (Lewis T. Flynn) writes:
::There was a discussion in this group recently concerning Amdahl's Rule
:...
::I guess the most useful thing to conclude from this is that the first
::rule of processor design is "Know Thy Workload". The second most useful
::thing is that there's no substitute for lots of research and
::measurement.
::
::Terry

:I do alot of work with many different systems mostly workstations lately
:and whiel most people recommend roughly following Amdahl's rule (and are
:probably not aware of it) I have noticed that doubling that figure
:is usually most efficient. For example a Decstation 3100 that runs at
:~12-14 MIPS running decwindows (X) runs much better with 24 MB of memory than
:the usual recommendation of 16 MB. This is just a casual observation hoewever
:and is not based on emperical data.

	Since most "natural" workstation applications tend to be processor
	intensive while general purpose computing applications (the kind
	that I understand Amdahl based his rule on) tend to be I/O intensive
	this makes sense.  

	This only goes to reinforce the need to "Know Thy Workload".

-- 
Jerry Gitomer at National Political Resources Inc, Alexandria, VA USA
I am apolitical, have no resources, and speak only for myself.
Ma Bell (703)683-9090  (UUCP:  ...uunet!uupsi!npri6!jerry )