Path: utzoo!mnetor!uunet!oddjob!hao!gatech!udel!burdvax!bpa!cp1!sarin!wb3ffv!howardl
From: howardl@wb3ffv.UUCP (Howard Leadmon )
Newsgroups: comp.sys.ibm.pc
Subject: Re: Help with a Seagate 251 which seems too slow
Message-ID: <525@wb3ffv.UUCP>
Date: 22 Jan 88 01:25:30 GMT
References: <3579@sdcc6.ucsd.EDU>
Distribution: comp.sys.ibm.pc
Organization: Fast Computer Service, Inc. - Middle River, MD
Lines: 39
Summary: Correct Interleave..

In article <3579@sdcc6.ucsd.EDU>, ir1@sdcc6.ucsd.EDU (ir1) writes:
> I am running an ATT6300 which for the purpose of this question is
> the same as an IBM XT. I was running a Seagate 225 20M hard disk
> which gave me a Norton Utility Index of 1.1. I have now switched to a 40M
> Seagate 251 with a WD WX1 controller, partioned into a small C,
> and a 20M D and E drive. (Partioning done with Speedstore.) The
> Norton Index on the 251 is .5, and stopwatch timings of program
> loading indicate that the new drive is half as fast as the old one. I didn't
> do the low level format and Seagate doesn't seem helpful (although
> they claim the 251 should be as fast as the 225). 
> 

   Hello,
 First off let me point out that generally the best interleave is determined
by the controller you are using, so you should look at the information you
recieved with the HD Controller. Now let me tell you about my experiences
with the various contorllers, and what we used with a ST-251. I installed
a Seagate ST-251 in an IBM-PC the other day, and the contorller that came
with the drive was a Western Digital WD1002-SWX series board (I think SWX).
After several re-formats we decieded the best interleave was 4:1. This was
tested using the CORE Harddrive test, and the throughput was about 130Kbytes
per second. When using the recomended 3:1 interleave, throughput dropped to
a mere 30Kbytes per second, and at 5:1 it was only down to 120Kbytes. This
proves that too short an interleave really hurts!! Anyway the other Western
Digital controllers I have worked with are the WD1003 and the WD1006 series.
The best interleave with the 1003 is 3:1 and gives a throughput of about 190
Kbytes per second. The GREAT controller (and the one I use) is the WD1006
series, and it is a 1:1 interleave track-cache controller. The WD1006 will
achive a throughput of nearly 400 Kbytes, and believe me you can tell when
copying large files. Well I hope this is of interest to some of you net
readers...



						Sincearly,
						Howard Leadmon
						Fast Computer Service, Inc.
						cp1!sarin!wb3ffv!howardl
						(301)-335-2206