RTC can't keep up the time

["Arnaud Lacombe" <lacombar%gmail.com@localhost>]

Hi Folks,

I noticed a weird bug on -current (5.99.5). The hardware is new, about
3 month old. I didn't noticed such behavour on the previous 5.99.1:

$ sudo ntpdate 0.pool.ntp.org; sleep 20; sudo ntpdate 0.pool.ntp.org
17 Dec 14:02:10 ntpdate[7729]: step time server 129.128.5.211 offset
13.333831 sec
17 Dec 14:02:33 ntpdate[8640]: step time server 129.128.5.211 offset
3.751196 sec

$ date; sleep 20; date
Wed Dec 17 14:02:33 EST 2008
Wed Dec 17 14:02:49 EST 2008

it seems that each 20 seconds, I lose 3.75 seconds.

I tested with an external timer, and the delay between the two date(1)
*is* 20 seconds.

Any hints ?

 - Arnaud