View Single Post
  #9   Report Post  
Posted to sci.electronics.repair
Bryce[_2_] Bryce[_2_] is offline
external usenet poster
 
Posts: 40
Default WTF with my computer clock?

Meat Plow wrote:

On Tue, 11 Aug 2009 14:55:14 GMT, "JB"
wrote:


"Meat Plow" wrote in message
...
On Tue, 11 Aug 2009 10:45:42 +0000 (UTC), root
wrote:

The damned thing loses about 20 minutes/day and has
so since the machine was new about 3 years ago.

My guess is that it isn't fixable, but maybe you
have some ideas.

TIA.

Windows XP and Vista and Linux all have a built in clock
sync with a time server.
Figure out how to set it to update every 6 hours or
less.

As far as the hardware is concerned it probably isn't
fixable but it's not the end of the world.


I don't get it. It is just stupid to require an "always
up" Internet connection for any kind of stability.


I suppose the unstupid thing would be to replace the
hardware?

(snip)

Begin by finding out which of the two clocks is the bad guy.

The CMOS clock runs continuously, powered from the PC power
supply when available and from the CMOS battery otherwise.
During start-up the O/S reads this hardware clock and uses
this value to initialize the software clock that is the date
and time source until the next startup.

A bum oscillator or low CMOS battery will cause hardware
clock errors and result in wrong-time initialization.

If the CPU misses servicing the clock interrupt or other bad
stuff, the operating system's idea of time will suffer, but
the hardware clock keeps right on ticking.

So, if you're losing time without a reboot, the CMOS is
innocent and the O/S and CPU aren't doing the right dance.
If the time is wrong from the gitgo, then the HW clock is
the culprit.

Bryce