[ntp:questions] Windows time question.

unruh unruh at wormhole.physics.ubc.ca
Tue May 3 20:02:50 UTC 2011


On 2011-05-03, David J Taylor <david-taylor at blueyonder.co.uk.invalid> wrote:
>> As the OP who started this (long and sometimes ammusing) thread...
>>
>> I do carry a GPS receiver with me, but sadly not PPS capable, I use it
>> for location determination/tracking/navigating etc.   Maybe I should
>> include a GPS18 or 16 in the already bulging Laptop bag I lug arround.
>
> Even better if there were on on a USB stick, and you had a handy USB 
> extension lead!

Unfortunately , AFAIK, usb is terrible for delivering a PPS-- ie no
interrupt lines-- the problem with having only two data lines (one beign
signal ground)
. 


>
> How critical is your time need?  If it's within minutes, then the PC's 
> clock is likely good enough.  If it's in the UK or Europe, I would be 
> surprised if pool servers did not get you well within the second - perhaps 
> within 100msec - particularly if you set the servers based on the country 
> you're in.  I suspect that if you need closer than tens of milliseconds, 
> carrying round a GPS 18x LVC (which I jokingly suggested) may actually be 
> necessary.  NTP was designed when connections were nothing like as good as 
> they are now, and is supposedly robust in those circumstances.  It is 
> designed for 24-hours operation, though.
>
> 73,
> David 
>




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