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

Richard B. Gilbert rgilbert88 at comcast.net
Sun Dec 4 17:03:33 UTC 2005

David J Taylor wrote:

>I run a number of NTP systems based on Windows, and normally all but the 
>Windows 2000 Workstation keep good time.  In particular, the Windows XP 
>SP2 system kept good time until about 14:00 UTC on Friday 2nd December.
>  http://www.david-taylor.myby.co.uk/mrtg/odin_ntp.html
>I asked myself what changed on the system and, as far as I know, the 
>answer is nothing!  Around that time, I was developing a program for 
>processing large images, and fed it an image which was too large.  Perhaps 
>coincidental - perhaps not.  The pagefile size is fixed at 2GB and seems 
>to still be the same.  I wondered if disk I/O had become switched from 
>UDMA to PIO, but its seems not.  I've checked for spyware and neither 
>SpyBot nor AdAware find anything other than cookies.  I don't see anything 
>unusual in Services.  I even did a system restore to around 12:58 (IIRC) 
>on the day in question, but this didn't cure the problem.
>I'm stuck!  Can you help?  Why would an otherwise good timekeeper become 
>degraded in this way?  The jitter figures (from ntpq -p) are in the 10 - 
>15 millisecond range, even for servers on the LAN, whereas other PCs on 
>the same LAN show jitter under a millisecond.  Lan traffic looks normal, 
>though.  The delay figures look normal as well.
>Any ideas?  (no, replacing XP is not an option!).
Do you have your systems configured to do "automatic updates".  If so, 
Microsoft may have installed a patch. . . .

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