computer components & hardware

HardwareBanter (http://www.hardwarebanter.com/index.php)

- General (http://www.hardwarebanter.com/forumdisplay.php?f=28)

- - Clock Discrepancy (http://www.hardwarebanter.com/showthread.php?t=200111)

June 3rd 20 09:15 PM

Clock Discrepancy

Atomic clock supposedly synced ( sp ? ) by radio to some standard from out west ( Denver ? ) is always at least 2 seconds behind the computer. I'd think they'd be spot on. Comments ?

Paul[_28_]

June 3rd 20 09:36 PM

Clock Discrepancy

wrote:
Atomic clock supposedly synced ( sp ? ) by radio to some standard from out west ( Denver ? ) is always at least 2 seconds behind the computer. I'd think they'd be spot on. Comments ?

OS not stated.

Control Panels : Date and Time
Internet Time
Update Now (time.nist.gov)

That's an NTPD update being done on the spot.

Now, compare standards again. Are they synced now ?

Even "national standard" time sources, have been off by 20 minutes,
under failure conditions. Keep your weather eye peeled for shenanigans.

*******

PC clock drifts after a sync event. All PCs do this,
because the clock on the motherboard is +/-100ppm.
That's a pretty big error, and a pretty grotesque
time reference source.

Windows Time syncs once a week (assuming time.nist.gov
is accessible and so on), allowing *plenty* of time for
accumulated drift after the sync is done.

The Windows clock subsystem does not "dribble out"
the drift rate. Some third party ntpd implementations,
adjust the local clock according to measured drift rate,
and this helps keep the deterministic drift to a minimum,
until a week has passed. Maybe every 15 minutes, such a
software might make a 0.01 second correction, or whatever
the first order drift rate happens to be.

Some of the drift is a "wander" of unknown direction and
magnitude. Even recording and analyzing such error, leads
to no better ability to predict it in the future. This
is the limit of what "blind correction" can do for you.

Summary: Do an immediate "sync" by clicking the button,
*then* check the time.

Paul

[email protected]

June 3rd 20 09:55 PM

Clock Discrepancy

A=20very=20complicated=20answer=20to=20a=20minor=2 0non-issue

It's=20always=20the=202+=20seconds

No=20consequence=20for=20anything.=20I=20was=20jus t=20curious

Using=20Windows=207

=20Summary:=20Do=20an=20immediate=20"sync"=20by=2 0clicking=20the=
=20button,
=20=20=20=20=20=20=20=20=20=20=20*then*=20check=2 0the=20time.

How=20do=20I=20do=20this=20?

Paul[_28_]

June 3rd 20 11:38 PM

Clock Discrepancy

wrote:
A very complicated answer to a minor non-issue

It's always the 2+ seconds

No consequence for anything. I was just curious

Using Windows 7

Summary: Do an immediate "sync" by clicking the button,
*then* check the time.

How do I do this ?

With the Update Now button.

https://i.postimg.cc/sDj6yZvB/update-now-button.gif

Paul

[email protected]

June 4th 20 12:15 AM

Clock Discrepancy

There=20in=20lies=20the=20rub.

My=20updating=20has=20been=20non-functional=20for=20a=20very=20lon=
g=20time.

It=20just=20indicates=20failed=20to=20update.

All=20my=20efforts=20at=20diagnosis=20and=20possib le=20remedy=20ha=
ve=20failed.

However=20there=20doesn't=20seem=20to=20any=20sign ificant=20conseq=
uences=20for=20this.

Paul[_28_]

June 4th 20 12:40 AM

Clock Discrepancy

wrote:
There in lies the rub.

My updating has been non-functional for a very long time.

It just indicates failed to update.

All my efforts at diagnosis and possible remedy have failed.

However there doesn't seem to any significant consequences for this.

That button is not Windows Update.

That button is an NTP time update.

You can open Command Prompt and do

nslookup time.windows.com

and see whether DNS resolves properly.

These nodes don't necessarily respond to "ping", because
that would enable various denial of service scenarios.
I can't guarantee that every time server is ping-able.

It could be that some service isn't running. Using
"services.msc" as an executable, look and see if "Windows Time"
service is running at the moment. Start it. GO back to the Update
button and try again.

Paul

All times are GMT +1. The time now is 11:53 AM.