[ntp:questions] Can NTP affect the time even when not running? (with platform details this time)

Wolfgang S. Rupprecht wolfgang+gnus20041124T165542 at dailyplanet.dontspam.wsrcc.com
Thu Nov 25 01:07:14 UTC 2004

Brad Knowles <brad at stop.mail-abuse.org> writes:
> 	Laptops are notorious for having "speed-step" type of
> technology that speeds up or slows down the processor as necessary for
> the workload and cooling requirements, and this plays holy hell with
> good timekeeping.

This is moving to mainstream processors too.  The desktop athlon64 has
such an arrangement.  Full-speed is currently between 1.8Ghz and
2.4Ghz depending on how good the processor tests.  Low speed / idling
is 800Mhz at a reduced voltage.  The power savings are immense (89
watts in high speed mode, and as low as 12 watts in low speed / low
voltage mode.)

Folks will want to stop using the CPU cycle counter for timekeeping
ASAP.  That trick just isn't going to work for much longer.  (AMD
boards do seem to have the new counter-timer chip which is CPU speed
independent and has a linear 64-bit counter.)

Wolfgang S. Rupprecht                http://www.wsrcc.com/wolfgang/
	 When you talk to musicians about pirates they think
		   you are talking about the RIAA.

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