[ntp:hackers] 8 seconds ever 15 minutes

Tuc tuc at ttsg.com
Sun Jun 22 08:05:12 PDT 2003


> tickadj is not usefull on FreeBSD.
>
	Seems that way. :)
>
> FreeBSD use what is called "timecounters".
> There are various "time" sources in a PC/Laptop and it might be that FreeBSD
> is not using the "best" one for your circumstances. Or maybe it just need
> a little help in figuring out the proper frequency.
> 
> You can see which time source is being used by typing:
> 
> sysctl kern.timecounter.hardware
>
himinbjorg# sysctl kern.timecounter.hardware
kern.timecounter.hardware: i8254
> 
> You can see which ones are available with:
> 
> sysctl machdep | grep freq
>
himinbjorg# sysctl machdep | grep freq
machdep.i8254_freq: 1193182
> 
> The TSC timecounter is very good on PCs that don't do power management,
> but a poor choice on machine, like notebooks, that play with the CPU
> frequency to tweak the power usage. There the i8254 is probably a better
> choice. On 5.x you can also use acpi. You can change the timecounter to
> use with the kern.timecounter.hardware sysctl and you can tweak the
> frequency by tweaking the machdep.*_freq value. For instance, I have
> this in the /etc/sysctl.conf file of one of my time servers:
> 
> machdep.tsc_freq=600111000
> kern.timecounter.hardware=TSC
> 
> Hope this helps. This should probably have been asked on the
> comp.protocols.time.ntp newsgroup.
> 
Sorry, I looked over the lists on ntp.org and this was the closest I found
to the right one. Theres no email<>c.p.t.n gateway?

Turns out I upgraded my BIOS from A02 to A10, and all of a sudden I'm .04 +/-
at most anymore. My ntpdrift FINALLY moved from 500.000 to 8.614.

		Thanks, Tuc/TTSG Internet Services, Inc.



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