Comment 11 for bug 553237

> on a side note I've found i have to disable cpu frequency scaling first to get a proper
> sampling of my clock skew
> without that what it gets can vary alot on each run

hm.. that cpu frequency comment makes me wonder, because I think I
have spread spectrum enabled, and probably that is what causes my
clock to shift so much:
http://lkml.indiana.edu/hypermail/linux/kernel/0410.1/1505.html
http://ubuntuforums.org/showthread.php?t=956263

"Otherwise, reboot your system and enter BIOS SETUP. Check if your
BIOS has a Front Side Bus (FSB) Spread Spectrum (SS) clocking option.
On many systems, this option is located in the "Advanced Chipset
Features" menu. If the option is present and enabled, disable it.
Boot Linux and observe the system clock over several hours to verify
if this has improved its accuracy."

I will disable:
- Spread spectrum
- D.O.T. (Dynamic Overclocking Technology)

I will purge:
- ntp
- adjtimex

I will leave the pc running for a while and let you know of my
results. Thanks for this lovely side note! :)