[ntp:questions] Can anyone interpret these loopstats?

Martin Burnicki martin.burnicki at meinberg.de
Tue Nov 27 08:36:17 UTC 2007


Ryan,

Ryan Malayter wrote:
> On Nov 23, 1:08 pm, "David J Taylor" <david-tay... at blueyonder.not-this-
> bit.nor-this-bit.co.uk> wrote:
>> In the event log NTP is showing errors: "Unable to initialise the .rnd
>> file", but I don't think that's key to the operation of NTP itself.  The
>> NTP service shows as running, and the W32time service as stopped.
>>
>> Thanks,
>> Puzzled from Edinburgh (a.k.a. David)
> 
> What are the Power Options settings in Vista? Can you try creating a
> custom power profile which prevents processor power management (in
> Vista, every default power profile - even the "High Performance"
> profile  - seems to use processor frequency scaling.)
> 
> If things work fine with processor frequency scaling turned off, that
> would be an interesting.

That's indeed an interesting point.
 
> Besides processor power managmeent, the power management options for
> the Indexing service as well as the multimedia power options could
> potentially affect ntpd, I suppose. (The former because of lost
> interrupts, and I know the Meinberg build uses multimedia timers on
> windows).

Please note that "the Meinberg build" is based on the official NTP sources.

The only thing the ntpd port for Windows does with the multimedia timers is
to set them optionally to highest resolution while the ntpd service is
running. 

This is just to avoid virtual steps in the system time returned by the
Windows API calls, when another program changed the MM timer resolution,
which still happened on Vista when I tried last time.

This MM feature is only enabled if the "-M" flag is given on the command
line for ntpd. This can be enabled or disabled in the GUI setup during
installation, or simply by editing the ntpd's ImagePath registry key. So it
can easily be disabled to see whether the behaviour changes.

Martin
-- 
Martin Burnicki

Meinberg Funkuhren
Bad Pyrmont
Germany




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