From owner-freebsd-hackers Sun Mar 31 12:35:14 2002
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Date: Sun, 31 Mar 2002 13:34:02 -0700 (MST)
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To: dp@penix.org
Cc: silby@silby.com, bicknell@ufp.org, hackers@FreeBSD.ORG
Subject: Re: GPS time.
From: "M. Warner Losh" <imp@village.org>
In-Reply-To: <Pine.LNX.4.43L0.0203311040090.8980-100000@saruman.xwin.net>
References: <20020331091304.U40871-100000@patrocles.silby.com>
<Pine.LNX.4.43L0.0203311040090.8980-100000@saruman.xwin.net>
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In message: <Pine.LNX.4.43L0.0203311040090.8980-100000@saruman.xwin.net>
Paul Halliday <dp@penix.org> writes:
: This is the answer I was kinda hoping for. I think that accuracy
: to ~100ms from a known source is a little more comforting than <1ms from a
: server that I have no control over. I am not maintaining a space program,
: just a dozen machines in my room that really serve no other purpose than
: personal entertainment.
Also keep in mind that the US governement reserves the right to turn
off GPS at any time to selected regions of the globe.
The problem with the large variation in time is that if you are trying
to use it for a NTP reference clock, bad things happen to the
algorythm and you get substantially worse performance than you would
otherwise.
Warner
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