Why are motherboard clock so inaccurate?

[Jerboy]

The CMOS clock on computer always gets thrown off faster than even a cheapest standalone clock. Why is this and why can't they match the accuracy of standard digital watch?

 

[HappyPuppy]

ECS K7S5A dead on after 2 months. Matter of fact, the CMOS clocks on all my computers have always been dead on or very close.

Do you maybe have a dead battery?

 

[PliotronX]

My CUSL2 loses (or gains) about 1-3 seconds each day. Thank goodness for the programs that update with timeservers.

 

[CraigRT]

I don't know if my MSI loses a second or 2 each day, that's piddles, doesn't even matter to me. that's one of those things that you'd just set one day after 6 months later just because it's not the same as the other clock in your room or something.. if it's losing alot, i can't explain why... a guy at work, his Asus P2B motherboard is losing about 10-15 mins per day! but the computer is functioning perfect... (Long live the P2B)

 

[bjc112]

mine loses about 20 seconds a day... oh well.. XP updates it every week or so!

 

[Jerboy]

<< mine loses about 20 seconds a day... oh well.. XP updates it every week or so! >>




:Q

No matter what computers, its never been as accurate as even my beater wrist watch($10).

 

[Beau]

Our security system on the building does the same thing.. it loses about an hour per month. Really annoying, and I can see a problem with trying to use the access time posted to the logs for a legal record too.

 

[Armitage]

<< The CMOS clock on computer always gets thrown off faster than even a cheapest standalone clock. Why is this and why can't they match the accuracy of standard digital watch? >>



I don't know, but they can be very bad!
I wouldn't rely on it for anything important.
I worked on a project once that needed very accurate time data. They ended up getting an external time reference. I don't remember how it was connected - serial port maybe.

 

[jamarno]

If the battery measures at least 3.0V, then try removing it overnight because some oscillators become unstable and need to be turned off completely. But some of the 32 KHz crystals (tiny silver cylinder with 2 wire leads at one end) aren't quite right for their oscillators, and replacing them with one from a cheap watch will improve the accuracy a lot.

 

[erub]

<< XP updates it every week or so. >>



Yup

 

[CStroman]

<<

<< XP updates it every week or so. >>



Yup >>



That can cause a problem if you're set to the wrong time zone. It took me a little while to figure out what was wrong.

 

[Armitage]

<< mine loses about 20 seconds a day... oh well.. XP updates it every week or so! >>



20 seconds a day is pretty big if you use that time for anything where accuracy is important. And XP updates every week mean that your clock will jump 3 minutes at the update time, right? Could make for some confusing logs.
Better to use an ntp service.

 

[corkyg]

I never consider them inaccurate. I calibrate mine with Atomic Clock once a month, and it never off by more than a few seconds.

 

[veryape]

The clock on my Aopen AK72 is and always has been perfect, and that's after two years of running this system as my main rig, and it's on constantly!!! I like Aopen, although I should probably be saying that I like whoever distributes their batteries because that is the reason most of your clocks are off, dead or dying cmos batteries.

 

[jaeger66]

Any $10 drugstore watch will keep better time than a $2000 PC and it has nothing to do with batteries. A wristwatch operates at one cycle per second, or thereabouts. The PC clock runs off the clock generator, and I'm not sure what those are up to these days...20MHz maybe? And when you try to keep time from a generator running 20 million times faster the little inaccuracies pile up quickly.

 

[Vinny N]

Wow I wonder why people are having so many problems?
I hope they're not running 2000 or XP and having their clock constantly offset by the timeservers on their domain or something? (saw this a lot)

I just sync'd with some time servers. Last time I sync'd was 19 days ago. The correction I needed for time lost/gained since then? -6.86 seconds.

How are people losing 20 seconds a day?