[ntp:questions] Linux 11-minute mode (RTC update)

Serge Bets serge.bets at NOSPAM.laposte.invalid
Wed Apr 9 10:34:05 UTC 2008

 On Monday, April 7, 2008 at 17:46:21 +0000, Unruh wrote:

> if it is true that the hwclock routine sets/reads the system clock
> better than does the kernel

Well, neglecting drift, hwclock is already way more accurate than the
kernel (several orders of magnitude better). And the kernel doesn't
handle RTC drift. Check if you doubt.

> that is up to  100PPM difference in the RTC between on and off.

Aren't you drawing a general rule from a single out of bounds maybe
dying example? I can provide a counter-example then. One Intel chipset
RTC here drifts at:

  +77.269 PPM powered-off during the night
  +78.531 PPM runtime at day

Which shows only 1.262 PPM variation between extreme conditions. That's
the most stable I could find, of course. Don't draw conclusions from it.

Serge point Bets arobase laposte point net

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