[ntp:questions] Regular spike_detect on syslog

Jan Ceuleers jan.ceuleers at computer.org
Sun Sep 16 11:48:59 UTC 2018


On 16/09/18 13:24, Sean Austin Critica wrote:
>  
>
> I’m running on bare metal HP Gen9 blade. I have started looking at the
> BIOS settings and as far as I can tell there are a lot of options that
> affect CPU frequency and they are turned on.
>
>  
>
> I will check tomorrow if ‘Spread Spectrum’ is available and is turned
> on as I don’t have access to the machine right now.
>


I assume that yours is a Class A device, where the need to resort to
spread spectrum is less (because the Class A EMC requirements aren't as
strict as the Class B requirements which apply to consumer devices), so
you may not find this option in the BIOS, in which case your problem is
caused by something else.
 
>
> I do know that settings like Intel Turbo Boost, and dynamic power
> control are on. Although HP support says that they are not aware of
> any settings that impact NTP on the host.
>
>  
>

Whereas these options do modulate the clock frequency, they do so with
the knowledge of the operating system. The OS is therefore able to take
that into account in its timekeeping (for example by selecting a
timekeeping clock source that remains constant notwithstanding Turbo
Boost and all the rest of it).


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