[ntp:questions] Re: NTP client on Windows platform provides less accurate results then on the UNIX or Linux. Why?

Ry malayter at gmail.com
Fri Mar 31 05:33:06 UTC 2006

How often are these boxes restarted? NTP seems to take a 8 hours or
more to really "settle". If you're rebooting the Windows machines
frequently (and you *should* be at least once per month to get MS
security patches), NTP will always perform worse in comparison with a
Linux box that is always on.

If your hardware has any power-management features enabled (Intel
SpeedStep, AMD CoolNQuiet, etc.), that would do it. Others may have
mentioned disabling ACPI in the BIOS, but you will also want to
checkDevice Manager to make sure you don't have speed-throttling "CPU
drivers" or other "system devices" installed or activated.

Finally, the WinXP firewall or other software firewall could be adding
small delays if it is enabled and CPU utilization isn't genreally low.
So could any host-based intrustion prevention, anti-spyware, or
antivirus software that scans live network connectios for threats
(e.g.Symantec Client Security). Also make sure the multimedia timers
are enabled during setup of NTPd.

For reference, right now my XP box is showing an offset of 22ms when
syncing with internet stratum-2 servers, although it has only been
running for about 6 hours (I hate to think what a P4 running 24/7 would
look like on my electric bill). Our Windows 2003 servers running ntpd
at the office typically maintain +/-1 ms offsets when syncing to nearby
stratum-1 servers after running for a few hours.

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