[ntp:questions] What level of timesynch error is typical on Win XP?
David J Taylor
david-taylor at blueyonder.co.uk.invalid
Thu Oct 21 15:07:22 UTC 2010
> The platforms in question are running Windows XP, not Vista or Windows
> 7. How does this change the answer?
NTP will switch on the multi-media timers in Windows XP and achieve the
best performance I have seen on Windows systems. Temperature (or perhaps
CPU load causing temperature change in your case) seems to be the limiting
factor in the peak offset.
> By the way, the hardware is a collection of 8-core HP Z800 workstations
> connected together by copper gigabit ethernet links and local hub, with
> one link going via the company network to the GPS network time server.
> Joe Gwinn
Beware the 1Gb/s adapter settings, as Dave Hart mentioned. You may find
you get better timekeeping performance setting them to 100Mb/s.
You might consider providing a local, more precise NTP server with
something like a small, fan-less Intel Atom system running FreeBSD and
synched across the network to your GPS time server. You might be able to
keep a small box like that in a more temperature controlled environment,
but even without it might provide a way of smoothing out any jitter due to
your remote connection to the GPS server.
Another thought is to send 1PPS across the network (an old RS-232 link,
perhaps, just used as a direct connection, not for serial data), and
duplicate the PPS feed to your remote server locally. Then make an RS-232
level driver to send PPS to all your workstations. They get the precise
seconds from the PPS, and the nearest-second time from the network.
More information about the questions