From owner-freebsd-current  Mon Dec 10  1:49:29 2001
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Date: Mon, 10 Dec 2001 01:49:23 -0800
From: Terry Lambert <tlambert2@mindspring.com>
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To: "David W. Chapman Jr." <dwcjr@inethouston.net>
Cc: Julian Elischer <julian@elischer.org>,
	Matthew Dillon <dillon@apollo.backplane.com>,
	Greg Lehey <grog@FreeBSD.ORG>,
	Daniel O'Connor <doconnor@gsoft.com.au>, sthaug@nethelp.no,
	freebsd-current@FreeBSD.ORG, j@uriah.heep.sax.de,
	joerg_wunsch@uriah.heep.sax.de
Subject: Re: "Dangerously dedicated" yet again (was: cvs commit: src/sys/kern 
 subr_diskmbr.c)
References: <200112100559.fBA5x2x43757@apollo.backplane.com> <Pine.BSF.4.21.0112092202050.27605-100000@InterJet.elischer.org> <20011210062338.GA51934@leviathan.inethouston.net>
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"David W. Chapman Jr." wrote:
> > > :> > IBM DTLA drives are known to rotate fast enough near the spindle
> > > :> > that the sustained write speed exceeds the ability of the controller
> > > :> > electronics to keep up, and results in crap being written to disk.
> >
> >
> > I would adssume it actually the tracks FURTHEREST from the spindle..
> 
> Wouldn't the linear speed be faster closer to the spindle at 7200 RPM
> than at the edge?

Linear speed is closes at the edge, but magnetic domain density
is higher at the spindle, for a uniform rotation rate.

I think that the electronics ended up being designed for the
average rate.

PS: The encoding frequency is higher at the spindle, as well.

-- Terry

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