[ntp:questions] Experimental ntpd for Windows

Terje Mathisen "terje.mathisen at tmsw.no" at ntp.org
Thu Jan 29 07:52:57 UTC 2009


Dave Hart wrote:
> Are you using ntpd on Windows and dissatisfied with its timekeeping?
> I have a patched ntpd with changes intended to improve its accuracy
> that could use some wider testing.  Source and binaries are linked to
> below.
> 
> Two changes are particularly noteworthy:
> 
> 1.  Code to disable the interpolation approach on systems where the
> Windows system clock is observed to have better than 5ms precision.
> Only Windows Vista so far has been observed with less than 10ms
> increments to the system time of day clock, and then only when some
> software (such as ntpd with -M) has raised the multimedia timer
> resolution.  This means -M is recommended by me for Vista users of
> this experimental version.  Without -M, ntpd may use interpolation,
> which will work until you browse to a Flash website or launch a Java

I've installed your version, and included -M in my startup parameters:

I get Event Log (Application) messages about stuff like:

System time quantum 1.000 msec, min. slew 6.410 ppm/s
Clock interrupt period 15.600 msec (startup slew 0.1 usec/period)
Performance counter frequency 14.318 MHz
MM timer resolution: 1..1000000 msec, set to 1 msec
ntpd 4.2.4p6 at DLH-QPC-o Jan 28 6:47:59.16 (UTC-08:00) 2009  (51)

which seems to me to indicate that your code is indeed running, but I 
don't get any 'filtered... QPC' messages at all?

Vista-64 sp1 btw.

Terje

-- 
- <Terje.Mathisen at tmsw.no>
"almost all programming can be viewed as an exercise in caching"




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