Path: utzoo!utgpu!watmath!clyde!att!cbnews!shurr
From: shurr@cbnews.ATT.COM (Larry A. Shurr)
Newsgroups: comp.sys.ibm.pc
Subject: Re: Disk Data Transfer Question
Message-ID: <2441@cbnews.ATT.COM>
Date: 2 Dec 88 20:10:43 GMT
References: <1228@dutesta.UUCP>
Reply-To: shurr@cbnews.ATT.COM (Larry A. Shurr)
Organization: AT&T Bell Laboratories (actually an APR consultant)
Lines: 29

In article <1228@dutesta.UUCP> franky@dutesta.UUCP (Frank W. ten Wolde) writes:
[Has AT&T "3600" (think you mean 6300) with ST251-1 and WD1002S-WX1.]
[Use interleave of 5 and gets transfer rate of ~100KB/sec.  True IBM PC']
[use interleave of 3 and get ~170KB/sec.  The PC runs at 4.77MHz and the]
[Olivetti (what he actually has and which is the same thing as an AT&T]
[6300) runs at 8MHz.]
>My questions are:

>    1. Is there someone out there who has the same problem?
>    2. Is there someone with an AT&T 3600 with a data rate
>       of 170K/s (and a corresponding interleave of 3)?
>    3. Is there someone who can tell me where the problem
>       originates and perhaps how to solve it?

Frank,  You've been had.  The Olivetti M24/AT&T 6300 has an 8086 CPU
running at 8MHz, but I understand that the bus runs at 4MHz (half the
system clock rate) and *NOT* 4.77MHz.  Consequently, your raw data
transfer rate is actually LESS than a real-but-slower IBM PC.  Here
at the Labs, 6300's seem to perform well with an interleave of 4 in
configurations similar to yours, but interleave factor 3 is a dog.
Thus, there a lot of "slow" 6300's around because their hard disks
came preformatted with an interleave factor of 3 and their owners
don't know enough to realize what is wrong.

regards, Larry
-- 
Signed: Larry A. Shurr (att!cbnews!shurr or osu-cis!apr!las)
Clever signature, Wonderful wit, Outdo the others, Be a big hit! - Burma Shave
(With apologies to the real thing.  Above represents my views only.)