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From: mph@rover.UUCP (Mark Huth)
Newsgroups: comp.sys.amiga
Subject: Re: Cheap disk drives
Message-ID: <712@rover.UUCP>
Date: Tue, 17-Nov-87 11:04:15 EST
Article-I.D.: rover.712
Posted: Tue Nov 17 11:04:15 1987
Date-Received: Fri, 20-Nov-87 07:34:32 EST
References: <73@mithras> <198@tahoma.ARPA>
Reply-To: mph@rover.UUCP (Mark Huth)
Organization: Motorola Microcomputer Division, Tempe, Az.
Lines: 15
Keywords: IBM Cheap

ST506 provides for hard disk data rates of 5Mb per second back to the
controller, most SCSI drives run at 10Mb per second.  This is the data
transfer rate, and has little to do with the perceived performance
when driven through the file system.  

A parameter which is noticed is the average access time, as this
generally is related to the seek time of the drive, and the current
file system does a lot of seeks.

The average access time varies from model to model.  Seagate 225 are
65ms, 251s are 40ms.  Other vendors have done better than this in
their newer hardware.  Drives with average access times around 28ms
are commonly available in larger capacity drives, both SCSI and ST506.

Mark Huth