Time sync.

I've got a load of Windows XP machines on a Windows 2003 network (single Forest / Domain / Site).
The machines seem to fall out of sync with each other, by just a little bit (ie 1 second) As far as I understand, Windows conforms to "loose sync" which means that its fine for the XP machines to be out of sync by up to 2 seconds before they are brought back in sync again.
Is there a way I can keep the machines in closer sync with each other (ie 1/2 a second or so) or do I have to invest in a 3rd party NTP software implementation?

Many thanks Ian

 

It's my understanding that when XP machines are members of a Domain that the DC handles the time keeping task.

 

The PC clocks should not gain/lose time very quickly unless you have some hardware issues. It then becomes a matter of how much additional network traffic you are willing to generate. I don't know any easy way to force a synch when the PC is a specific amount different than your time server but if you get a feel for how quickly this happens after a synch, then something here should suit.

http://support.microsoft.com/kb/q223184/

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W32Time\Parameters

One of the values is

Period : REG_DWORD or REG_SZ
Used to control how often the time service synchronizes. If a string value is specified, it must be one of special ones listed below.
0 = once a day
65535, "BiDaily" = once every 2 days
65534, "Tridaily" = once every 3 days
65533, "Weekly" = once every week (7 days)
65532, "SpecialSkew" = once every 45 minutes until 3 good synchronizations occur, then once every 8 hours (3 per day) [default]
65531, "DailySpecialSkew" = once every 45 minutes until 1 good synchronization occurs, then once every day
freq = freq times per day

 

I have got the XP machines to sync every 5 minutes at the moment, but the problem is, that synchronisation is only to within 2 seconds (as far as I understand)

eg the XP machine contacts the DC to sync its time, it finds out that it is 1 second apart, so therefore considers it to be in sync and doesn't adjust the clock.

Because Windows conforms to "loose synchronisation" the clocks can be up to 2 seconds apart (in a site) and that is considered to be "in sync ", and no adjustment will be made to the time until the clocks exceeds the 2 second threshold.

What I need is a way to force a true sync without having this 2 second margin.

Thanks I.

 

ian187--I know nothing about the problem, so just a stab in the dark. Do you think it might help to have each PC synch directly with an external time synch source, such as
http://www.winsite.com/bin/Info?1000000034325
or
http://www.google.com/search?hl=en&rls=GGLD,GGLD:2004-31,GGLD:en&q=time+Sync+software&spell=1

 

Welshjim,
problem is the clocks seem to go out of "skew" and it doesn't matter what they sync to, because when they sync there is an error margin of 2 seconds.

So if the clock is only 2 seconds out, then as far as XP is concerned "it IS in sync" and won't bother doing anything about it!

Thnx anyway

 

This Utility (not free) runs as a service and says it "Sets all clients within 250 milliseconds of timeserver."