NTP on Windows Vista - NTP

This is a discussion on NTP on Windows Vista - NTP ; 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 Could one of the NTP experts suggest why initial stability should degenerate in ...

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Thread: NTP on Windows Vista

  1. NTP on Windows Vista

    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

    Could one of the NTP experts suggest why initial stability should
    degenerate in this way? The drift file is being updated regularly, and
    there are no unusual events in the event log. The W32time service is
    disabled.

    Thanks,
    David



  2. Re: NTP on Windows Vista

    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.

  3. Re: NTP on Windows Vista

    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.

    Cheers,
    David



  4. Re: NTP on Windows Vista

    David Woolley wrote:
    []
    > Can I just confirm that this system is connected to its time sources
    > only by ethernet, and that that ethernet has low latency drivers?


    I meant to comment that it has no special Ethernet drivers, just what
    comes with Windows Vista. But as the steps are sometimes 50msec or more,
    I would not have thought that it was latetncy....

    Cheers,
    David



  5. Re: NTP on Windows Vista

    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?

  6. Re: NTP on Windows Vista

    Richard B. Gilbert wrote:
    []
    > Have you considered reinstalling Windows XP?


    No, because this is a Vista testbed, and the objective is to get NTP
    working here as well as it does on all the other Windows PC systems (NT4,
    2000, XP etc.).

    David



  7. Re: NTP on Windows Vista

    David J Taylor wrote:
    > Richard B. Gilbert wrote:
    > []
    >> Have you considered reinstalling Windows XP?

    >
    > No, because this is a Vista testbed, and the objective is to get NTP
    > working here as well as it does on all the other Windows PC systems (NT4,
    > 2000, XP etc.).
    >
    > David
    >
    >


    My condolences!

  8. Re: NTP on Windows Vista

    Richard B. Gilbert wrote:
    > David J Taylor wrote:
    >> Richard B. Gilbert wrote:
    >> []
    >>> Have you considered reinstalling Windows XP?

    >>
    >> No, because this is a Vista testbed, and the objective is to get NTP
    >> working here as well as it does on all the other Windows PC systems
    >> (NT4, 2000, XP etc.).
    >>
    >> David
    >>
    >>

    >
    > My condolences!


    No need for that, Richard. So far Vista has run everything I've thrown at
    it (with the exception of NTP) with no significant problems. I've run
    some quite unusual software, including a satellite download link of some
    20GB per day. It's actually quite a nice OS to use, and feels smooth in
    operation. With the majority of today's new PCs running Vista, it's an OS
    which I cannot afford ignore.

    Cheers,
    David



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