[ntp:questions] Idea to improve ntpd accuracy

Leon McCalla leonmccalla at hotmail.com
Sun Feb 28 05:11:04 UTC 2016


I've been monitoring this thread for a while and i have a few comments.
1) I think on average the TX queue delay inside an ethernet card is going to be way smaller than the delay observed on the general internet. NTPd's primary algorithms compensate really well for jitter and delay already so the last order of magnitude expected to be gained by doubling the packets may not really materialize. A lot more could be gained by implementing QOS and making NTP packets the #1 priority.

2) Temp changes definitely affect the CPU clock speed and consequently NTP's accuracy. You can implement algorithms that compensate for ambient temperature but what about localized temperature such as load related temperature changes. Is the temp sensor really that close to the oscillator for consistent results? again this could vary from motherboard to motherboard.

I think the best way to really improve NTP's accuracy would be to focus on the development of an oven controlled oscillator combined with a 64bit latchable counter on a usb stick. A simple USB device, when mass produced, would bring any PC to nanosecond accuracy for a few dollars. Knowing that the demand is there, Maxim or Texas Instruments or one of those other large IC manufacturers may be willing to produce such a device based on an email from this group

Leon


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