[ntp:questions] Re: Time sync with milliseconds with Windows XP

Al Dykes adykes at panix.com
Tue Sep 6 14:25:06 UTC 2005


In article <p06200779bf434442c598@[10.0.1.210]>,
Brad Knowles <brad at stop.mail-abuse.org> wrote:
>At 5:52 AM -0700 2005-09-06, Magnus wrote:
>
>>  We have some servers that are sending data to each other 10 times per
>>  second. They need to be time synced and my question is if the NTP
>>  client in Windows are sufficient exact for the application.
>>
>>  If no, how can I get time sync with milliseconds in Windows XP?
>
>	To the single millisecond level?  You can't.  Beyond typical 
>hardware configuration problems, the OS itself loses too many 
>interrupts on a busy machine.  If the machine is doing absolutely 
>nothing else, and you've configured the hardware correctly, you might 
>get it into the single millisecond range, but that kind of defeats 
>your purpose.
>
>	If the machine is doing anything at all, even with the hardware 
>configured correctly, the best you can hope for is to get accuracy in 
>the 10-100ms range, most likely closer to the middle or top end of 
>that range.
>
>	And that's with "real" NTP on the machine.  Running w32time or 
>whatever crap Microsoft ships, you're not going to get anywhere close 
>to that.
>


What about getting a WWV receiver that generates a PPS serial signal
and usuing a Y cable to connect it to both machines running real ntp.

This depends, of course, on being in a location where you can get a
WWV (or GPS) signal and have some money to spend on a receiver. 


-- 
a d y k e s @ p a n i x . c o m 

Don't blame me. I voted for Gore.




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