From owner-freebsd-hackers  Sun Sep  7 18:55:44 1997
Return-Path: <owner-freebsd-hackers>
Received: (from root@localhost)
          by hub.freebsd.org (8.8.7/8.8.7) id SAA25923
          for hackers-outgoing; Sun, 7 Sep 1997 18:55:44 -0700 (PDT)
Received: from counterintelligence.ml.org (mdean.vip.best.com [206.86.94.101])
          by hub.freebsd.org (8.8.7/8.8.7) with ESMTP id SAA25918;
          Sun, 7 Sep 1997 18:55:40 -0700 (PDT)
Received: from localhost (jamil@localhost)
	by counterintelligence.ml.org (8.8.7/8.8.5) with SMTP id SAA01090;
	Sun, 7 Sep 1997 18:54:21 -0700 (PDT)
Date: Sun, 7 Sep 1997 18:54:20 -0700 (PDT)
From: "Jamil J. Weatherbee" <jamil@counterintelligence.ml.org>
To: Hoffmann Yen-Wei Liu <ywliu1@tao.sinanet.com.tw>
cc: question@FreeBSD.ORG, hackers@FreeBSD.ORG
Subject: Re: Kernel clock runs inaccurately
In-Reply-To: <199709080124.JAA14004@tao.sinanet.com.tw>
Message-ID: <Pine.BSF.3.96.970907185323.997B-100000@counterintelligence.ml.org>
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII
Sender: owner-freebsd-hackers@FreeBSD.ORG
X-Loop: FreeBSD.org
Precedence: bulk


I don't think this has any bearing on the problem but if you are connected
to a network run xntpd to keep gettimeofday() clock synced with a master
server (like the navy or something)



On Mon, 8 Sep 1997, Hoffmann Yen-Wei Liu wrote:

> Hi,
> 
>   Sorry, I don't know if this question fits in questions or hackers 
> mailing list.
> 
>   I just got myself a new AMD k6-200, and I found out a major problem :
> it runs about 30 seconds faster per day. So two days later, it runs
> 2 minutes faster. However, the CMOS clock runs around 2 seconds slower
> per day. This is acceptable to me.
> 
>   After fooling around with CLK_USE_I8254_CALIBRATION and 
> CLK_USE_I586_CALIBRATION options, I can either make it run 2 seconds slower
> per *hour*, or several seconds faster per minutes, but not to a acceptably
> inaccurate ranage. The boot verbose flag gives me the following figure inf:
> 
> ...
> Calibrating clock(s) ... i586 clock: 199932094 Hz, i8254 clock: 1194681 Hz
> Calibrating clock(s) ... i586 clock: 199931374 Hz, i8254 clock: 1194663 Hz
> CPU: AMD K6 (199.93-MHz 586-class CPU)
>   Origin = "AuthenticAMD"  Id = 0x561  Stepping=1
>   Features=0x8001bf<FPU,VME,DE,PSE,TSC,MSR,MCE,CX8>
> ...
> 
> 
> Also, even looking into isa/i386/clock.c cannot give me too many clues.
> 
> In a word,
> 
> 1) I know Pentium motherboard clock isn't accurate. But is there any workaround
> for me to set options or modify clock.c to make the kernel clock runs in
> a acceptably inaccurate range ?
> 
> 2) Does changing to a new motherboard with better quality help ?
> 
> 3) I run OSS/FreeBSD commercial sound driver. Does this possibly matter ?
> 
> 
> THanks for your attention.
> 
> 
> Yen-Wei Liu
>