NTP Jitter & Offset
Values are offset +20 microseconds because MRTG can't render negative
values in a graph. So the true 0 mark is the center of the graph.
- The time difference between two clocks, relative to a selected reference clock. Represents the amount to adjust the local clock to bring it into correspondence with the reference clock. Offset is a temperature-affected, as temperature affects the quartz oscillator.
- The estimated time error of the system clock measured as an exponential average of RMS time differences. Limited by the Precision of the clock
- How precisely Stability and Accuracy can be maintained within a particular timekeeping system. Another way of thinking of this, is as the smallest unit of time a clock that can be read from the clock. This is a number indicating the precision of the various clocks, in seconds rounded to the next larger power of two; for instance, a 50-Hz (20 ms) or 60-Hz (16.67 ms) power-frequency clock would be assigned the value -5 (31.25 ms), while a 1000-Hz (1 ms) crystal-controlled clock would be assigned the value -9 (1.95 ms). The clock in the Raspberry Pi has a precision of -19 (0.000001907s, or about 2 microseconds).