# ntpd cpu usage



## ggf (Mar 28, 2010)

On the 7.1-RELEASE when ftp'ing a backup file from the server, ntpd seems to run a high cpu.
CPU is like 18%, Has anyone seen this before?

Any ideas on this?


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## anomie (Mar 30, 2010)

How significant are your clock corrections at that time? Are you saying this CPU usage is _only_ high while ftp-ing a file..?


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## fronclynne (Mar 30, 2010)

I would guess that ntpd doesn't really consume that much cpu just skewing the clock (though I could be quite mistaken).  Here, ntpd has consumed a grand total of 23 seconds over the last two days, which honestly seems a bit high, considering that my window manager has consumed 6 seconds over the same two days.

I know back when I was running i586 class machines that ntpd seemed like a bit much overhead just to keep the clocks in synch for nfs (I tended use use timed(8) with a master machine on the network synching via ntp).  Then again, to quote ntpd(8)

```
The ntpd utility does most computations in 64-bit floating point arith-
     metic and does relatively clumsy 64-bit fixed point operations only when
     necessary to preserve the ultimate precision, about 232 picoseconds.
     While the ultimate precision is not achievable with ordinary workstations
     and networks of today, it may be required with future gigahertz CPU
     clocks and gigabit LANs.
```
so maybe it is a lot more computationally intensive than I suspected.


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