Path: utzoo!attcan!uunet!cbmvax!steveb
From: steveb@cbmvax.UUCP (Steve Beats)
Newsgroups: comp.sys.amiga
Subject: Re: Hard disk speed question.
Message-ID: <4156@cbmvax.UUCP>
Date: 30 Jun 88 14:49:15 GMT
References: <6957@cup.portal.com>
Reply-To: steveb@cbmvax.UUCP (Steve Beats)
Organization: Commodore Technology, West Chester, PA
Lines: 21

In article <6957@cup.portal.com> Michael_J_Dedina@cup.portal.com writes:
>Would a 30ms hard drive give you significantly better performance than a 60 or
>80ms drive on an Amiga (I'd be using it with an A500 and the -MAX- interface)?
>I remember hearing that it wouldn't make much difference on a PC/XT, because
>disk access time was insignificant compared to other bottlenecks in the system.
>-------------------------
>Mike Dedina

Definitely yes!  I've been working on a Quantum drive with an average 19ms
seek time for about a month.  That sucker really flies.  In the course of
doing some testing and diagnostic work, I had to use a couple of drives that
were rated at 65ms and 80ms average access times respectively.  The difference
was spectacular (or apalling, whatever your point of view is).  Basically, once
you start getting into SCSI transfer rates, a long seek time becomes a major
detriment to the overall performance and "feel" of the drive.  Bear in mind,
if you are getting 500-600K burst transfer rates from your drive, that evens
out to about 1ms per 512 byte block.  Therefore, stepping to the next track
on an 80ms seek time drive just cost you 40K/s of throughput, regardless of
interleaving.  A point to ponder, no ?

	Steve