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From: eugene@ames.UUCP (Eugene Miya)
Newsgroups: net.arch
Subject: Re: Memory Law
Message-ID: <1253@ames.UUCP>
Date: Thu, 14-Nov-85 18:52:51 EST
Article-I.D.: ames.1253
Posted: Thu Nov 14 18:52:51 1985
Date-Received: Sun, 17-Nov-85 06:25:49 EST
References: <764@bu-cs.UUCP>
Organization: NASA-Ames Research Center, Mtn. View, CA
Lines: 17

Barry Stein's >8 MB vax problem:

This is Ivan "Sutherland's Corollary" to the von Neumann bottleneck.
He published in Scientific American's special issue on microelectronics:
if you have a process with big memory, size N, then at any instant
N-1 pieces of memory are not being used.  For multiprocessors with n
CPUs with n << N, then N-n is not much better.

For parallel processors, there is also Amdahl's law which says if you
throw infinite parallelism at a problem, the serial portions become
the bottleneck.

From the Rock of Ages Home for Retired Hackers:
--eugene miya
  NASA Ames Research Center
  {hplabs,ihnp4,dual,hao,decwrl,allegra}!ames!aurora!eugene
  emiya@ames-vmsb