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From: timothym@tekigm2.TEK.COM (Timothy D Margeson)
Newsgroups: comp.sys.ibm.pc
Subject: Re: Interleave factor on a 6300
Message-ID: <2049@tekigm2.TEK.COM>
Date: Tue, 11-Aug-87 14:17:14 EDT
Article-I.D.: tekigm2.2049
Posted: Tue Aug 11 14:17:14 1987
Date-Received: Thu, 13-Aug-87 07:04:14 EDT
References: <2928@mtgzz.UUCP> <1844@ttrdc.UUCP> <300@cpsc6b.cpsc6a.att.com>
Reply-To: timothym@tekigm2.UUCP (Timothy D Margeson)
Organization: Tektronix, Inc., Beaverton, OR.
Lines: 30

Hi,

OKAY FOLKS - Interleave of hard disk systems is to compensate for inefficient
drive controllers AND computer bus structures (primarily DMA channels).

Disks themselves DO NOT and CANNOT effect what interleave is best for a given
system (except in extreme cases where a disk does not meet some standards such
as ST506 or ST412 or SCSI, but is still used in systems using those standards).

So, forget about what disk drive you have when considering interleaves, more
important is the controller and bus structure and related timimgs.

For example, using the same disk drive, but two different controllers on a
Compaq Deskpro (8086), I have seen interleaves of 4:1 and 2:1 as optimums for
the different controllers.

Even on the same controller with a different BIOS, I have seen a difference
of 4:1 and 2:1 giving the fastest transfer rates.

Finally, for a given system, the best way to find what interleave is best is
trial and error. Start by formatting the disk with an interleave of 1:1, and
work your way up to 6:1. Somewhere in between you will find an interleave that
gives the best transfer rates.


-- 
Tim Margeson (206)253-5240
PO Box 3500  d/s C1-937                          @@   'Who said that?'  
Vancouver, WA. 98668
{amd..hplabs}cae780!tektronix!tekigm2!timothym (this changes daily)