[ntp:questions] Re: How application get precise time from Win NT/XP system time that synchronies to NTP
terje.mathisen at hda.hydro.com
Wed Mar 30 10:03:23 UTC 2005
Roger Chou ??? wrote:
> If my application polls the system time once every tick, i.e. 10
> millisecond, can I get nanosecond resolution and accuracy that NTP can
No. No way. Never.
What you might get is millisecond.
WinNT started out with a beautiful system clock definition, using 100 ps
(yes, 0.1 ns!) as the resolution, then they immediately destroyed it by
a combination of two mistakes:
1) Interpolation between ticks simply isn't done.
2) The clock is in the HAL (Hardware Abstraction Layer) below the OS, so
even a regular kernel driver cannot fix it.
- <Terje.Mathisen at hda.hydro.com>
"almost all programming can be viewed as an exercise in caching"
More information about the questions