Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!samsung!zaphod.mps.ohio-state.edu!rpi!crdgw1!crdos1!davidsen
From: davidsen@crdos1.crd.ge.COM (Wm E Davidsen Jr)
Newsgroups: comp.arch
Subject: Re: Ignorance speaks loudest (was:Computers for users not programmers)
Message-ID: <3179@crdos1.crd.ge.COM>
Date: 6 Feb 91 16:20:18 GMT
References: <1991Feb4.210853.22139@odin.corp.sgi.com> <1652@hpwala.wal.hp.com> <409@bria> <13252@lanl.gov> <1991Feb4.154607.8606@ux1.cso.uiuc.edu> <1991Feb5.020456.1119@ux1.cso.uiuc.edu> <1991Feb5.172529.11162@odin.corp.sgi.com>
Reply-To: davidsen@crdos1.crd.ge.com (bill davidsen)
Organization: GE Corp R&D Center, Schenectady NY
Lines: 23

In article <1991Feb5.172529.11162@odin.corp.sgi.com> archer@elysium.esd.sgi.com (Archer (Mr. Slug) Sully) writes:

| Have you actually done benchmarks and performance comparisons that prove 
| this?

  You can do this as a "thought experiment." I previously said that AsIO
is a win when CPU and IO time are roughly equal. Let's consider a
program which runs 90 sec CPU, and 60 sec IO. Without async IO the job
runs 90+60=150 sec. With AsIO it runs 90 (more or less).

  Since UNIX buffers write to disk files, all output of that type is
AsIO, and that's why some programs run much faster in UNIX than DOS on
the same hardware. Some versions of UNIX also do read ahead on input,
making that AsIO, too. And some versions of UNIX allow the user to
request AsIO explicitly.

  AsIO is standard on output in all UNIX versions and available for
input or explicit user call for a number. Another strawman.

-- 
bill davidsen	(davidsen@crdos1.crd.GE.COM -or- uunet!crdgw1!crdos1!davidsen)
  "I'll come home in one of two ways, the big parade or in a body bag.
   I prefer the former but I'll take the latter" -Sgt Marco Rodrigez