Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!uflorida!haven!adm!cmcl2!phri!ccnysci!alexis
From: alexis@ccnysci.UUCP (Alexis Rosen)
Newsgroups: comp.sys.mac
Subject: Re: Mac II disk I/O
Keywords: disk transfer rate
Message-ID: <1312@ccnysci.UUCP>
Date: 24 Feb 89 08:35:51 GMT
References: <13392@duke.cs.duke.edu>
Reply-To: alexis@ccnysci.UUCP (Alexis Rosen)
Organization: City College of New York
Lines: 16


A few weeks ago, Ed Darken (erd@cs.duke.edu) posted a note describing an
experiment he did benchmarking disk transfer speeds on the Macintosh. He
described the unusual (and disturbing) result that when he transfered up to
256 blocks, he got results in the 350-380 KBytes per second, but transfers
of 512 blocks displayed speeds an order of magnitude slower (only *28* KBytes
per second).

Has anyone figured out what cuases this? Was the experiment faulty, or has
Ed uncovered a serious flaw in the File System, or is it some other possibility
that I haven't thought of? (He defragmented his disk, so that's not it.)
One thing I do know it that it's not the hard disk he used- those Wrens can
take data considerably faster than the Mac can spit it out.

Alexis Rosen
alexis@ccnysci.uucp