[EMAIL PROTECTED] wrote: > On Dec 3, 3:34 am, [EMAIL PROTECTED] (David > Woolley) wrote: >> In article <[EMAIL PROTECTED]>, >> >> [EMAIL PROTECTED] wrote: >>> QueryPerformanceCounter() directly off the hardware. Windows >>> scheduling has no impact here, the drawbacks of tick counts do not >> Windows scheduling will cause uncertainty in the time you get from >> your SNTP requests which you use to calibrate the performance counters. >> (It will also cause uncertainties in the time of whatever real world >> event is associated with the times being recorded by your software.) >> > > Windows scheduling will NOT cause any bigger uncertainty than many > other factors including network delays or scheduling on my Linksys > router > (probably Unix-like OS) that relays all my incoming/outgoing IP > traffic. >
Then you have no idea. There is plenty of evidence to disprove this. I have plenty of suspicious pieces that may be the cause of the issues including interrupts and message pumping. > The most important thing is that my code will be able to measure > fairly > consistently the time between sending a request and receiving a > reply > for ***all*** servers in microseconds. I will use at least five > servers. > It would not be possible with TICKS but it is possible with high > frequency > counters because they operate on different principle as stated. This > is the > key difference!!! Consequently, it will be possible to estimate the > drift of the > PC counter and come up with servers' polling frequencies that > satisfy my > reqs for accuracy. > > So do not make it more complicated than it is. The rest belongs to > the > algorithims I will use and you do not know them, and I am not ready > to > discusss them. > That's okay, we don't need to know. If you can prove you get better results then I'm sure you will let us know. We would welcome something better but you need to show it really is better for most (if not all) cases that ntp deals with. Danny _______________________________________________ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
