[ntp:questions] Re: Windows timekeeping - sudden degradation - why?

David J Taylor david-taylor at blueyonder.co.not-this-bit.nor-this-part.uk.invalid
Thu Dec 8 07:16:04 UTC 2005

David J Taylor wrote:
> Martin Burnicki wrote:
>> If the MM timer is set constantly to high resolution then you should
>> observe a little more jitter than with default resolution, but the
>> large steps should go away. So as a test you just might to start
>> Quicktime and watch if the offset settles down.

Well, with the MM timer permanently running (from 17:00 Wednesday) I can 
report that things are /much/ better, see:


- the offset first shot up to 120ms, but is now gently decaying towards 

- the jitter figures seem much better, around 1 (LAN servers) - 2ms (WAN 

- the drift value has changed from -65 down to -9.3ms.

I would certainly like the option, for this system at least, of running 
with the MM timers permanently in its high resolution mode.

I would also be interested in determining which program is switching the 
MM timer speed, and thereby upsetting the otherwise excellent timekeeping 
on this system.  I wonder if there's a relatively easy way to determine 


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