[ntp:questions] ntp-4.2.6p5 on Win 7 x64

Martin Burnicki martin.burnicki at meinberg.de
Wed Jul 30 15:31:54 UTC 2014

Nick wrote:
> Thanks to all the useful suggestions on here it's all working pretty well
> now on Win 7 x64.


> Reducing the DPC latency by setting the Win 7 power management profile
> made the most difference.

I think this is some important information to keep in mind for us.

> Using ntp-4.2.7p450-win-x86-bin-djt tweaked with imagecfg to run on the
> last CPU.
> Running with the -M switch to force nptd to use the Windows clock directly.

Just for the records:

The -M switch lets ntpd call a Windows API function which sets the 
Multimedia Timer to highest resolution as long as the service is 
running, so there are no additional side effects when other applications 
do this, too.

"Windows clock directly" means ntpd doesn't try to interpolate the 
Windows system time between updates. This is the default behavior for 
current versions of ntpd if ntpd detects that the Windows system time 
steps forward in 1 ms units instead of 16 ms intervals.

Martin Burnicki

Meinberg Funkuhren
Bad Pyrmont

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