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From: ephraim@think.com (Ephraim Vishniac)
Newsgroups: comp.sys.mac.system
Subject: Re: interleave factor for Mac Plus
Message-ID: <1991Jun17.142818.13927@Think.COM>
Date: 17 Jun 91 14:28:18 GMT
References: <1991Jun15.134800.2012@welch.jhu.edu>
Sender: news@Think.COM
Reply-To: ephraim@think.com
Organization: Thinking Machines Corporation, Cambridge MA, USA
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In article <1991Jun15.134800.2012@welch.jhu.edu> francois@welch.jhu.edu (Francois Schiettecatte) writes:
>I have a question about interleave factor for hard disks. 
>Given the speed of the Mac Plus when accessing the SCSI 
>bus, what would be the optimal interleave factor I should 
>use to format my hard drive.
>
>I have a standard Mac Plus with a 80 Mb quantum drive. 
>I know enough about interleave factor to know that if 
>it is less than optimal, performance can degrade a lot.
>On my PC I could use the formating program to test the 
>hard drive and let the program choose the best interleave
>factor but I have looked at both Silverlinning and the 
>Apple SC setup and neither offer that possibility, of 
>testing the drive I mean, they can both set the interleave
>factor.

The customary advice for the Mac Plus is to use 3:1 interleaving. This
advice applies only to drives without caching, however. Since you've
got a Quantum drive, you've probably got an on-board cache. Last I
looked, such drives won't even let you tinker with the interleaving
since you can only hurt performance that way. 

-- 
Ephraim Vishniac    ephraim@think.com   ThinkingCorp@applelink.apple.com
 Thinking Machines Corporation / 245 First Street / Cambridge, MA 02142
        One of the flaws in the anarchic bopper society was
        the ease with which such crazed rumors could spread.