Path: utzoo!utgpu!water!watmath!clyde!cbosgd!mandrill!neoucom!wtm
From: wtm@neoucom.UUCP (Bill Mayhew)
Newsgroups: comp.sys.att
Subject: Re: Seagate 255 in a 6300
Summary: Norton "SI C:" isn't a good indicator
Message-ID: <935@neoucom.UUCP>
Date: 13 Jan 88 06:24:18 GMT
References: <3574@sdcc6.ucsd.EDU>
Distribution: comp.sys.att
Organization: Northeastern Ohio Universities College of Medicine
Lines: 29


The data transfer rate of the Seagate 225 and the Seagate 251 is
500K bits/sec.  Norton "SI C:" is probably going to rate both
drives about the same.

For the ST-225, the average seek time is about 85 mS.  For the
ST-251, it is about 35 mS.  Programs such as CORETEST or PC Lab's
BENCH can analyze the seek time.  The latter is available from PC
Magazine.

Picking an interleave factor is dependent on controller.  With
Seagate drives, and the DTC controller that comes the 6300, 3 or 4
seems to give the best performance for us.  There is a program
called LFORM on the PC6300 diagnostics disk that lets you do a low
level format.  It can be a study in hurry up and wait, but trying
several interleaf factors is the only way to be sure.

RLL drives can be even more mysterious.  I have had to use anywhere
from 1 to 7 on the PC6300.  Controllers such as the SMS OMTI5627
give you tracks of 26 sectors, while the WD WX-A give you "virtual"
tracks of 17 sectors as seen by the host, eventhough the drive
itself has 26 sectors per track and fewer actual tracks.  The WX-A
gives really weird reports with CORETEST.

Different applications programs and different versions of DOS will
also react differently to various interleaf factors due to high
level delays in buffering, etc.

--Bill