Re: Time change in Linux OS

From: Alexander Ulyanov (uav_at_urmail.ru)
Date: 11/20/04 

Date: Sat, 20 Nov 2004 14:29:20 +0500

On 2004-11-20, Joe <joe@jretrading.com> wrote:
> In message <slrncptq0b.j2.uav@trinity.local.net>, Alexander Ulyanov
><uav@urmail.ru> writes
>>On 2004-11-19, Jean-David Beyer <jdbeyer@exit109.com> wrote:
>>> If it is your cmos clock being inaccurate, you might check the battery.
>>> They tend to go bad after a while, but since all the ones I have seen
>>> lately have been lithium cells, I would expect them to last longer than
>>> you would keep the mother board (5 to 7 years).
>>
>>BTW, what else can be the cause of CMOS clock problems? My clock (SuperMicro
>>P6DBE motherboard) has huge drift, and if I turn off the machine completely
>>with the switch on ATX power supply, the clock and all CMOS settings are
>>reset. I tried replacing the battery (twice), and it didn't help.
>
> How much is huge drift? I'd expect the crystal used here to be within
> about 50 parts per million of the nominal frequency, so less than five
> seconds a day error. If it's significantly more than this, together with
> the reset problem, I'd say it was a faulty RTC chip or crystal. Crystals
> are not the pure single-frequency devices many people think, and most
> can be overdriven into another oscillation mode that can be several
> percent off nominal frequency. Alternatively, a seriously faulty crystal
> could drag down the battery voltage with mains power off, and corrupt
> the RAM.

Well, the clock slows down several times (but not stops completely AFAICT)
while the system is down. It might be faulty chip/crystal; I've bought this
motherboard in the second-hand shop. 

-- 
Alexander Ulyanov, maintainer of PosBand roguelike
E-mail: uav AT urmail DOT ru            Web:    http://orthanc.chat.ru/pos/
"Think of a number, any number. -- Er, five. -- Wrong!"
    -- Marvin the Paranoid Android, "Life, The Universe, And Everything"

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