[ntp:questions] May 2013 Windows Update causing rapid 'ntpd' drift

starlight.2013q2 at binnacle.cx starlight.2013q2 at binnacle.cx
Sat May 18 13:50:35 UTC 2013


Just installed this month's Windows Update
patches on an old/slow Windows XP laptop
(1.5GHz Pentium-M) and it appears to have
damaged Windows 'ntpd' time-keeping.

Has anyone else observed this?

Before the patch 'ntpd' frequency was -15.761
PPM.  After the patches 'ntpd' frequency
went to -500 PPM and the system was still
gaining time so fast that 'ntpd' reset the
time between -1.5 and -5 seconds every fifteen
minutes.  This went on for 12 hours after the
system was rebooted.  No change in the running
applications and very light load most of the

Restarted 'ntpd' with the same -g parameter
and the problem persisted.

Restarted 'ntpd' with the -M option added and it
looks like it's doing ok now at around -55 PPM,
but -M has its down-sides so I prefer to avoid
using it if possible.

Running a somewhat older version 4.2.4p4
against two local CDMA time servers.  Generally
get offsets under 100 microseconds.
The version running here is patched to allow
a one-second polling interval, which I've
found necessary to obtain decent time-keeping
with Windows.

My best guess is that the problem results from
kernel-mode 'Win32k.sys' driver patch
KB2829361 aka MS13-046


Installed three other patches at the same time
but two are for IE and one is for Active-X
and don't seem likely culprits.  In case
someone suspects otherwise, they are
KB2847204, KB2829530, KB2820197.  The other
May patches were installed three days ago
since rebooting was not required for them.

Any thoughts or comments are appreciated.


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