In part 1 yesterday I went through all of the work needed to measure NTP and PTP accuracy between two computers on my desk using an oscilloscope. I demonstrated that PTP was accurate to a mean of 4 ns with 2 ns of standard deviation. Under ideal circumstances NTP was only slightly worse at 8–10 ns with a SD of 12–20 ns, depending on the test setup. I measured these with extremely high NTP polling rates, thousands of times more frequent than Chrony’s defaults. I ran a few tests with slow...
