[ntp:questions] Use ntpd as a daemon so that it continuously disciplines clock, no

David J Taylor david-taylor at blueyonder.co.uk.invalid
Mon Jan 17 19:36:43 UTC 2011


> How much CPU it has used right after start? Is it more than fifth of
> the 0.484 (which would be spent in 0.5 days)?

I don't know.  On another, less powerful, single-core PC, it's used 3.5s 
total CPU since December 24.

> Here, ntpd -q takes 14 milliseconds of CPU, including system time.
>
> Note that CPU power consumption depends on which sleep state it's in
> and it usually takes a lot of time to switch to/from deeper states, so
> it's more energy efficient to load CPU once for 0.5 seconds than 50000
> times for 10 microseconds.
>
> -- 
> Miroslav Lichvar

Miroslav, as Bill (unruh) says, launching a process involves a lot more 
than CPU - e.g. disk access.  Far more energy to launch (as it will likely 
be out of any disk cache) than the microsecond of CPU a steady running 
ntpd may use every second.

Cheers,
David 




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