Re: Fast I/O

Article View: comp.arch

Article #11718

#11718

From: Marc Auslander
Date: Tue, 21 May 1991 13:12

12 lines
1182 bytes

The old System 370 rule of thumb for I/O capacity was 1 instruction
per BIT of I/O.  The ratio is called (at least in IBM) E/B, spoken "E
over B".  Less than one was I/O intensive, greater than one cpu intensive.

A risc workstation running a real 10 mips today might be capable of
100 4k disk transfers a second, which is about 3 megabits.  So E/B is
about 3.  In other words, by the old standards, workstations are optimized
for computation - which is in fact correct.
--


Marc Auslander       <marc@watson.ibm.com>

Technical Details

Message-ID: <MARC.91May21081226@marc.watson.ibm.com>

Path: arc1-ca.pugleaf.net!utzoo!utgpu!news-server.csri.toronto.edu!rpi!think.com!spool.mu.edu!uunet!bywater!arnor!arnor!marc

References: <97b302n807vo01@JUTS.ccc.amdahl.com> <13096@pt.cs.cmu.edu> <WAYNE.91May19211810@dsndata.uucp>

Show Full Headers

Complete Article Headers

Path: arc1-ca.pugleaf.net!utzoo!utgpu!news-server.csri.toronto.edu!rpi!think.com!spool.mu.edu!uunet!bywater!arnor!arnor!marc
From: marc@watson.ibm.com (Marc Auslander)
Newsgroups: comp.arch
Subject: Re: Fast I/O
Message-ID: <MARC.91May21081226@marc.watson.ibm.com>
Date: 21 May 91 13:12:26 GMT
Article-I.D.: marc.MARC.91May21081226
References: <97b302n807vo01@JUTS.ccc.amdahl.com> <13096@pt.cs.cmu.edu>
 <WAYNE.91May19211810@dsndata.uucp>
Sender: news@watson.ibm.com (NNTP News Poster)
Organization: IBM T.J. Watson Research Center, Hawthorne, New York
Lines: 12
In-Reply-To: wayne@dsndata.uucp's message of 20 May 91 01:18:10 GMT
Nntp-Posting-Host: marc

Reply to Parent Message