Major Clock Drift

[pardsbane at offthehill.org (Josh Pollak)]

On Aug 30, 2004, at 8:56 AM, dsr at tao.merseine.nu wrote:

> On Mon, Aug 30, 2004 at 08:48:08AM -0400, Josh Pollak wrote:
>> Thanks, I'll use this. I would still like to know what's up with my
>> clock though. This much drift is not normal.
>
> It certainly is.
>
> The RTC in your machine is probably rated at 100 parts per
> million maximum failure. Multiply by 86,400 seconds per day, 100 ticks
> per second, and you get an assumed clock drift of 8.64 seconds
> per day.
>
> Anything better than that is simply your RTC doing better than
> specified.

Thats over a full minute of drift in one week. I find that hard to 
believe. Perhaps the RTC is inaccurate as a trade off for providing so 
many ticks per second, but I've never seen a computer's clock drift 
this quickly, even when we weren't running NTP.