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Old October 26th 05, 11:03 PM
 
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Default Why aren't computer clocks as accurate as cheap quartz watches?

Why do the battery powered clocks in personal computers tend to keep
worse time than quartz watches, even the $1 ones?

The computer batteries measure fine, at least 3.15V.

I thought that the problem was temperature swings in the computers
(25-38C), but a couple of cheapo watches taped inside the computers
kept better time.


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Old October 26th 05, 11:37 PM
John Doe
 
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Default Why aren't computer clocks as accurate as cheap quartz watches?

Maybe the same reason we didn't have built-in clocks until after there
were five dollar LCD wris****ches. I don't know.

My current clock is very accurate (MSI mainboard).

wrote:

Why do the battery powered clocks in personal computers tend to keep
worse time than quartz watches, even the $1 ones?

The computer batteries measure fine, at least 3.15V.

I thought that the problem was temperature swings in the computers
(25-38C), but a couple of cheapo watches taped inside the computers
kept better time.



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Old October 26th 05, 11:57 PM
Anthony Fremont
 
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Default Why aren't computer clocks as accurate as cheap quartz watches?


somebody wrote
Why do the battery powered clocks in personal computers tend to keep
worse time than quartz watches, even the $1 ones?


Who is the manufacturer? I only use Gigabyte(mostly) or MSI (sometimes)
motherboards. I find the clocks to be reasonably accurate. My guess
would be that the OEM didn't ground the crystal case or use the proper
guard ring techniques for noise reduction. Do you find that they run
fast or slow?


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Old October 27th 05, 12:25 AM
Don Bruder
 
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Default Why aren't computer clocks as accurate as cheap quartz watches?

In article . com,
wrote:

Why do the battery powered clocks in personal computers tend to keep
worse time than quartz watches, even the $1 ones?

The computer batteries measure fine, at least 3.15V.

I thought that the problem was temperature swings in the computers
(25-38C), but a couple of cheapo watches taped inside the computers
kept better time.


Dunno if it's still true in PC-land - I've been living in a Mac world
for a LONG time now - but when I was playing with them years ago, the
battery-backed real-time clock was read once at startup to set the
computer's software clock, which then kept time by counting clock
interrupts generated by the motherboard timing circuitry. That
interrupt, like any other "not non-maskable" interrupt, can be blocked
out for various reasons by various things, causing the software clock to
lose time. Usually, the amount of "lost" time isn't really noticable
except on "continuously on" machines. But with long periods between
restarts, heavy use of software (or firmware... The blame may not be in
your clock, but in your ROM code) that disables interrupts often or for
extended periods, and/or no intervention (be it human or software)
happening, it can grow to substantial amounts of time surprisingly quick.

Immediately after startup, the clock SHOULD be reasonably close to
right, since it will have been freshly set from the battery powered
clock, but after a while, it *WILL* go wonky unless steps are taken to
correct the drift - It's just the nature of the beast.

--
Don Bruder -
- If your "From:" address isn't on my whitelist,
or the subject of the message doesn't contain the exact text "PopperAndShadow"
somewhere, any message sent to this address will go in the garbage without my
ever knowing it arrived. Sorry... http://www.sonic.net/~dakidd for more info
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Old October 27th 05, 01:03 AM
George
 
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Default Why aren't computer clocks as accurate as cheap quartz watches?

Same reason El Cheapo watches don't run Windows!!

On 26 Oct 2005 15:03:04 -0700, wrote:

Why do the battery powered clocks in personal computers tend to keep
worse time than quartz watches, even the $1 ones?

The computer batteries measure fine, at least 3.15V.

I thought that the problem was temperature swings in the computers
(25-38C), but a couple of cheapo watches taped inside the computers
kept better time.




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