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Date: Tue, 11 Jun 1996 10:18:21 +1000
From: Bruce Evans <bde@zeta.org.au>
Message-Id: <199606110018.KAA02186@godzilla.zeta.org.au>
To: bde@zeta.org.au, nate@sri.MT.net
Subject: Re: CLOCK stuff at bootup
Cc: current@freebsd.org
Sender: owner-current@freebsd.org
X-Loop: FreeBSD.org
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>> Because defining one or both might work better.  Using sysctl to set the
>> actual (current) value might work better still.

>Umm, what am I supposed to set using sysctl?  I don't remember ever
>seeing this kind of detail in old email.

Clock nominal frequencies.

>> The i8254 clock determines long term accuracy.  Run for a while and
>> determine the drift and/or the time daemon adjustments.

>How?

Compare the output of `date` with an accurate clock or look in the time
deaemon log files.

>> Use sysctl to
>> specify the i8254 clock frequency that minimizes the drift and/or the

>How?

Look in the output of `sysctl -a` to find the relevant variable and set
it as usual.

>> The i586 clock determines intra-clock-interrupt times.  Specify the i586
>> clock frequency that minimizes the jitter in getttimeofday().

>How?

First find the frequency.  Set it as above.

Bruce