On Jan 29, 4:52 am, ma...@ntp.isc.org (Danny Mayer) wrote: > Dave Hart wrote: > > Take 2: > > > On Jan 28, 11:52 pm, Terje Mathisen <"terje.mathisen at tmsw.no"> > > wrote: > >> 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 > > > Notice the observed quantum 1 msec is less than the threshold I > > mentioned, so interpolation is disabled. You'll also notice a > > precision = 1000.0 usec log line, where with interpolation that number > > is much less than 1000. Your system should keep better time than it > > did with stock ntpd. If you can avoid any program that changes > > multimedia timers, you would probably get more precise ntpd > > timekeeping without -M, allowing interpolation to be used, however any > > MM timer use and the interpolation will perform very badly. > > >> 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....@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? > > > Yeah, that's part of the interpolation. If you want to see them, > > leave off -M (and avoid Flash, Quicktime, etc). > > If you are going to do this you MUST take account of Flash, Quicktime > and other multimedia otherwise it's not an acceptable solution. > Stability and accuracy of the clock are extremely important otherwise we > wouldn't be using ntp.
I'm a bit fuzzy on what I MUST do. I've been exhorting that running without -M on Vista invites brokenness. If stability is extremely important, run with -M on Vista. If accuracy is extremely important and you are sure there will be no apps increasing the multimedia timer resolution, without -M may make you happier. Most likely, Windows Server 2008 has exactly the same behavior as Vista. It's entirely reasonable on a server to know that you won't run Flash, Quicktime, or Java. Cheers, Dave Hart _______________________________________________ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
