Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!usc!wuarchive!decwrl!sgi!vjs@rhyolite.wpd.sgi.com
From: vjs@rhyolite.wpd.sgi.com (Vernon Schryver)
Newsgroups: comp.sys.sgi
Subject: Re: Time (is fleeting, Maaaadness takes its toll)
Summary: use timetrim
Message-ID: <72069@sgi.sgi.com>
Date: 13 Oct 90 05:11:05 GMT
References: <206355EEFDFF000D92@NRCNET.NRC.CA>
Sender: guest@sgi.sgi.com
Organization: Silicon Graphics, Inc., Mountain View, CA
Lines: 25

In article <206355EEFDFF000D92@NRCNET.NRC.CA>, SERRER@nrcm3.nrc.ca (Martin Serrer) writes:
> Just a curiosity question.
> 
>   Why is it that a $75K workstation (IRIS 4D50/GT) cannot keep time as
> accurately as an el-cheepo $5 wrist watch? Mine seems to gain about 3 minutes
> per week.


At last, a customer saying what I've been saying for years!  Oh, well.

There is an easy solution, provided you are running 3.3 or better.  (3.3.1
is better for other reasons.)  You can trim the system's clock by adjusting
"timetrim" in /usr/sysgen/master.d/kernel.  A good place to start for many
4D70's is -450000.  Simply determine how much time your system has gained
or lost in the last several days, convert that to a signed number of
nanoseconds/seconds, and edit the configuration file.  Your value of
3 minutes/7 days or 180*10**9 nsec/ 604800 seconds suggest a value of -300000
would be a good start for your machine.

Timed(1M) and timeslave(1M) describe how the system clock can be
automatically trimmed.


Vernon Schryver
vjs@sgi.com