[ntp:questions] NTP on Windows Vista

Richard B. Gilbert rgilbert88 at comcast.net
Fri Jun 20 13:05:22 UTC 2008

David J Taylor wrote:
> David Woolley wrote:
>> David J Taylor wrote:
>>> Yesterday I undated my Windows Vista system to Service Pack 1, and
>>> whilst NTP initially appeared to work correctly, it soon developed
>>> an oscillating state.  See:
>>>   http://www.satsignal.eu/ntp/NTP-on-Windows-Vista.html
>> They look like damped oscillations, so the questions are:
>> - why are you getting time steps;
>> - why is the response not critically damped.
>> Can I just confirm that this system is connected to its time sources
>> only by ethernet, and that that ethernet has low latency drivers? Apart 
>> from that one might suspect some complex power management
>> feature.
>> Under damping tends to indicate that ntpd is miscalculating the
>> frequency correction.  On Windows, the API it uses directly controls
>> the software clock rate.
> Thanks for your reply, David.
> Yes, the only connections to time sources are via Ethernet, and this PC 
> used to be fine when it ran Windows XP with a very similar configuration. 
> You can see what it was like last year, before November when Vista was 
> installed, here:
>   http://www.satsignal.eu/mrtg/gemini_ntp.html
> The ntpq output shows that it is synced to my stratum-1 server.  Other PCs 
> work well from this same server:
>   http://www.satsignal.eu/mrtg/daily_ntp.html
> According to SIW (System Information for Windows) the clock interrupts are 
> at 15msec intervals.  As far as I know, the only power management is on 
> the display, which is switched off after 20 minutes.  No disk power-down, 
> or hibernation.
> I had wondered if there was any clue in "it seemed OK immediately after 
> reboot", or whether that was just luck.

Have you considered reinstalling Windows XP?

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