[ntp:questions] Is 24PPM an Excessive Real-Time Clock Correction?
David T. Ashley
dta at e3ft.com
Thu Jul 5 20:19:49 UTC 2007
"Richard B. Gilbert" <rgilbert88 at comcast.net> wrote in message
news:468D4A70.9030508 at comcast.net...
> David T. Ashley wrote:
>> Any insight into whether 24 PPM is excessive for my server?
> Consider that a computer manufacturer typically spends something like $2
> US on the components for the clock! Consider, also, that they provide no
> way to adjust the clock hardware. Computers are designed to compute, not
> to keep time. The original IBM PC and PC/XT did not even have a clock; if
> you wanted a clock it was an add-on at extra cost from a third party.
> 24 PPM is pretty good. Anything up to a hundred or two will usually work
> just fine.
Thanks. Interesting. It seems to be a really steady error, i.e. seems to
always be between 24 PPM and 24.5 PPM.
I think I'll write a little software to plot it at a sampling frequency of
once per hour. I'm wondering if it varies by time of day, temperature, etc.
David T. Ashley (dta at e3ft.com)
http://www.e3ft.com (Consulting Home Page)
http://www.dtashley.com (Personal Home Page)
http://gpl.e3ft.com (GPL Publications and Projects)
More information about the questions