NTPsec

Kong

Report generated: Thu Jan 16 14:59:01 2025 UTC
Start Time: Thu Jan 9 14:59:00 2025 UTC
End Time: Thu Jan 16 14:59:00 2025 UTC
Report Period: 7.0 days

Daily stats   Weekly stats   Live GNSS Data   24 Hour Scatter Plots: ( )

Local Clock Time/Frequency Offsets

local offset plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Local Clock Time Offset -428.997 -119.659 -47.048 -2.431 43.492 109.040 601.468 90.540 228.699 46.150 -2.078 µs 0.8697 42.31
Local Clock Frequency Offset 11.426 11.503 11.548 11.944 13.595 13.760 13.963 2.047 2.257 0.482 12.023 ppm 2.398 8.986

The time and frequency offsets between the ntpd calculated time and the local system clock. Showing frequency offset (red, in parts per million, scale on right) and the time offset (blue, in μs, scale on left). Quick changes in time offset will lead to larger frequency offsets.

These are fields 3 (time) and 4 (frequency) from the loopstats log file.



Local RMS Time Jitter

local jitter plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Local RMS Time Jitter 7.787 10.505 12.599 21.403 44.106 74.698 134.781 31.507 64.194 11.811 23.778 µs 3.213 19.22

The RMS Jitter of the local clock offset. In other words, how fast the local clock offset is changing.

Lower is better. An ideal system would be a horizontal line at 0μs.

RMS jitter is field 5 in the loopstats log file.



Local RMS Frequency Jitter

local stability plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Local RMS Frequency Jitter 3.657 5.073 6.266 12.109 45.694 133.990 238.733 39.428 128.917 21.253 17.491 ppb 4.973 32.55

The RMS Frequency Jitter (aka wander) of the local clock's frequency. In other words, how fast the local clock changes frequency.

Lower is better. An ideal clock would be a horizontal line at 0ppm.

RMS Frequency Jitter is field 6 in the loopstats log file.



Local Clock Time Offset Histogram

local offset histogram plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Local Clock Offset -428.997 -119.659 -47.048 -2.431 43.492 109.040 601.468 90.540 228.699 46.150 -2.078 µs 0.8697 42.31

The clock offsets of the local clock as a histogram.

The Local Clock Offset is field 3 from the loopstats log file.



Local Temperatures

local temps plot

Local temperatures. These will be site-specific depending upon what temperature sensors you collect data from. Temperature changes affect the local clock crystal frequency and stability. The math of how temperature changes frequency is complex, and also depends on crystal aging. So there is no easy way to correct for it in software. This is the single most important component of frequency drift.

The Local Temperatures are from field 3 from the tempstats log file.



Local Frequency/Temp

local freq temps plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Local Clock Frequency Offset 11.426 11.503 11.548 11.944 13.595 13.760 13.963 2.047 2.257 0.482 12.023 ppm 2.398 8.986
Temp /dev/sda 42.000 44.000 44.000 47.000 49.000 50.000 51.000 5.000 6.000 1.540 46.583 °C
Temp /dev/sdb 32.000 33.000 34.000 36.000 38.000 39.000 40.000 4.000 6.000 1.416 35.699 °C
Temp LM0 48.000 49.000 49.000 54.000 58.000 59.000 60.000 9.000 10.000 2.784 53.765 °C
Temp LM1 38.250 39.875 42.375 45.875 72.125 74.609 77.750 29.750 34.734 7.232 47.540 °C
Temp LM10 25.000 25.000 25.000 25.000 25.000 25.870 26.000 0.000 0.870 0.102 25.010 °C
Temp LM11 60.000 61.000 61.000 62.000 63.000 64.000 65.000 2.000 3.000 0.778 62.313 °C
Temp LM12 2.000 3.000 5.000 13.000 21.000 23.000 24.000 16.000 20.000 4.601 13.195 °C
Temp LM13 25.000 25.000 25.000 25.000 25.000 25.000 26.000 0.000 0.000 0.097 25.009 °C
Temp LM14 41.000 42.000 42.000 44.000 45.000 46.000 46.000 3.000 4.000 0.911 43.662 °C
Temp LM15 33.000 34.000 35.000 37.000 61.000 63.000 66.000 26.000 29.000 6.324 38.662 °C
Temp LM16 65.500 66.500 66.500 67.500 68.500 69.000 69.500 2.000 2.500 0.583 67.588 °C
Temp LM17 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 °C
Temp LM18 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 °C
Temp LM19 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 °C
Temp LM2 38.250 40.000 41.250 43.500 71.250 74.000 80.750 30.000 34.000 7.652 46.242 °C
Temp LM20 38.250 39.750 42.375 45.750 72.169 74.500 77.500 29.794 34.750 7.230 47.512 °C
Temp LM21 65.625 66.500 66.750 67.750 68.750 69.000 69.500 2.000 2.500 0.561 67.722 °C
Temp LM22 32.000 33.000 34.000 36.000 38.000 39.000 40.000 4.000 6.000 1.380 35.733 °C
Temp LM23 63.850 64.850 64.850 67.850 69.850 69.850 70.850 5.000 5.000 1.505 67.922 °C
Temp LM3 42.000 44.000 44.000 47.000 49.000 50.000 51.000 5.000 6.000 1.537 46.598 °C
Temp LM4 46.850 47.850 48.850 49.850 50.850 52.850 54.850 2.000 5.000 1.053 50.086 °C
Temp LM5 46.850 47.850 48.850 49.850 50.850 52.850 54.850 2.000 5.000 1.062 50.098 °C
Temp LM6 54.850 55.850 56.850 57.850 60.850 66.850 72.850 4.000 11.000 1.888 58.448 °C
Temp LM7 46.850 47.850 48.850 49.850 50.850 52.850 54.850 2.000 5.000 1.053 50.105 °C
Temp LM8 41.000 42.000 42.000 44.000 45.000 46.000 46.000 3.000 4.000 0.912 43.663 °C
Temp LM9 33.000 34.500 35.500 37.500 50.000 51.500 52.000 14.500 17.000 3.418 38.028 °C

The frequency offsets and temperatures. Showing frequency offset (red, in parts per million, scale on right) and the temperatures.

These are field 4 (frequency) from the loopstats log file, and field 3 from the tempstats log file.



Local GPS

local gps plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
nSats 4.000 7.000 8.000 11.000 14.000 15.000 17.000 6.000 8.000 1.682 11.006 nSat -0.1371 3.06
TDOP 0.710 0.850 0.940 1.380 2.460 3.610 26.900 1.520 2.760 0.559 1.497 4.079 66.89

Local GPS. The Time Dilution of Precision (TDOP) is plotted in blue. The number of visible satellites (nSat) is plotted in red.

TDOP is field 3, and nSats is field 4, from the gpsd log file. The gpsd log file is created by the ntploggps program.

TDOP is a dimensionless error factor. Smaller numbers are better. TDOP ranges from 1 (ideal), 2 to 5 (good), to greater than 20 (poor). Some GNSS receivers report TDOP less than one which is theoretically impossible.



Server Offsets

peer offsets plot

The offset of all refclocks and servers. This can be useful to see if offset changes are happening in a single clock or all clocks together.

Clock Offset is field 5 in the peerstats log file.



Server Offset 2001:470:e815::24 (pi4.rellim.com)

peer offset 2001:470:e815::24 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2001:470:e815::24 (pi4.rellim.com) -475.291 -133.833 -61.247 8.801 83.626 158.980 624.705 144.873 292.813 59.175 10.477 µs 0.9254 26.98

The offset of a server in seconds. This is useful to see how the measured offset is behaving.

The chart also plots offset±rtt, where rtt is the round trip time to the server. NTP can not really know the offset of a remote chimer, NTP computes it by subtracting rtt/2 from the offset. Plotting the offset±rtt reverses this calculation to more easily see the effects of rtt changes.

Closer to 0s is better. An ideal system would be a horizontal line at 0s. Typical 90% ranges may be: local LAN server 80µs; 90% ranges for WAN server may be 4ms and much larger.

Clock Offset is field 5 in the peerstats log file. The Round Trip Time (rtt) is field 6 in the peerstats log file.



Server Offset 2001:470:e815::8 (spidey.rellim.com)

peer offset 2001:470:e815::8 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2001:470:e815::8 (spidey.rellim.com) -1,093.232 -896.159 -658.425 -2.587 311.385 473.061 750.773 969.810 1,369.220 283.484 -47.718 µs -1.08 4.336

The offset of a server in seconds. This is useful to see how the measured offset is behaving.

The chart also plots offset±rtt, where rtt is the round trip time to the server. NTP can not really know the offset of a remote chimer, NTP computes it by subtracting rtt/2 from the offset. Plotting the offset±rtt reverses this calculation to more easily see the effects of rtt changes.

Closer to 0s is better. An ideal system would be a horizontal line at 0s. Typical 90% ranges may be: local LAN server 80µs; 90% ranges for WAN server may be 4ms and much larger.

Clock Offset is field 5 in the peerstats log file. The Round Trip Time (rtt) is field 6 in the peerstats log file.



Server Offset 2001:67c:1270:0:dea6:32ff:feaf:803b (khronos.mikieboy.net)

peer offset 2001:67c:1270:0:dea6:32ff:feaf:803b plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2001:67c:1270:0:dea6:32ff:feaf:803b (khronos.mikieboy.net) -16.541 -0.834 -0.417 -0.073 0.404 2.014 2.505 0.821 2.848 0.579 -0.038 ms -11.72 353.3

The offset of a server in seconds. This is useful to see how the measured offset is behaving.

The chart also plots offset±rtt, where rtt is the round trip time to the server. NTP can not really know the offset of a remote chimer, NTP computes it by subtracting rtt/2 from the offset. Plotting the offset±rtt reverses this calculation to more easily see the effects of rtt changes.

Closer to 0s is better. An ideal system would be a horizontal line at 0s. Typical 90% ranges may be: local LAN server 80µs; 90% ranges for WAN server may be 4ms and much larger.

Clock Offset is field 5 in the peerstats log file. The Round Trip Time (rtt) is field 6 in the peerstats log file.



Server Offset 204.17.205.1

peer offset 204.17.205.1 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 204.17.205.1 -1.682 -1.435 -1.039 0.021 0.502 0.664 1.086 1.541 2.099 0.423 -0.040 ms -1.311 5.262

The offset of a server in seconds. This is useful to see how the measured offset is behaving.

The chart also plots offset±rtt, where rtt is the round trip time to the server. NTP can not really know the offset of a remote chimer, NTP computes it by subtracting rtt/2 from the offset. Plotting the offset±rtt reverses this calculation to more easily see the effects of rtt changes.

Closer to 0s is better. An ideal system would be a horizontal line at 0s. Typical 90% ranges may be: local LAN server 80µs; 90% ranges for WAN server may be 4ms and much larger.

Clock Offset is field 5 in the peerstats log file. The Round Trip Time (rtt) is field 6 in the peerstats log file.



Server Offset 204.17.205.16

peer offset 204.17.205.16 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 204.17.205.16 -584.029 -138.393 -51.983 11.282 72.957 154.442 735.280 124.941 292.835 56.127 10.577 µs 0.1329 36.49

The offset of a server in seconds. This is useful to see how the measured offset is behaving.

The chart also plots offset±rtt, where rtt is the round trip time to the server. NTP can not really know the offset of a remote chimer, NTP computes it by subtracting rtt/2 from the offset. Plotting the offset±rtt reverses this calculation to more easily see the effects of rtt changes.

Closer to 0s is better. An ideal system would be a horizontal line at 0s. Typical 90% ranges may be: local LAN server 80µs; 90% ranges for WAN server may be 4ms and much larger.

Clock Offset is field 5 in the peerstats log file. The Round Trip Time (rtt) is field 6 in the peerstats log file.



Server Offset 204.17.205.30

peer offset 204.17.205.30 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 204.17.205.30 -479.202 -167.723 -99.239 -18.323 48.535 109.556 542.357 147.774 277.280 57.784 -20.182 µs 0.7856 25.62

The offset of a server in seconds. This is useful to see how the measured offset is behaving.

The chart also plots offset±rtt, where rtt is the round trip time to the server. NTP can not really know the offset of a remote chimer, NTP computes it by subtracting rtt/2 from the offset. Plotting the offset±rtt reverses this calculation to more easily see the effects of rtt changes.

Closer to 0s is better. An ideal system would be a horizontal line at 0s. Typical 90% ranges may be: local LAN server 80µs; 90% ranges for WAN server may be 4ms and much larger.

Clock Offset is field 5 in the peerstats log file. The Round Trip Time (rtt) is field 6 in the peerstats log file.



Server Offset 2405:fc00::1 (robusta.dcs1.biz)

peer offset 2405:fc00::1 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2405:fc00::1 (robusta.dcs1.biz) -0.466 0.178 2.189 4.329 5.009 5.199 5.658 2.820 5.020 1.011 3.973 ms -1.454 4.973

The offset of a server in seconds. This is useful to see how the measured offset is behaving.

The chart also plots offset±rtt, where rtt is the round trip time to the server. NTP can not really know the offset of a remote chimer, NTP computes it by subtracting rtt/2 from the offset. Plotting the offset±rtt reverses this calculation to more easily see the effects of rtt changes.

Closer to 0s is better. An ideal system would be a horizontal line at 0s. Typical 90% ranges may be: local LAN server 80µs; 90% ranges for WAN server may be 4ms and much larger.

Clock Offset is field 5 in the peerstats log file. The Round Trip Time (rtt) is field 6 in the peerstats log file.



Server Offset 2604:a880:1:20::17:5001 (ntp1.glypnod.com)

peer offset 2604:a880:1:20::17:5001 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2604:a880:1:20::17:5001 (ntp1.glypnod.com) -1.441 -1.201 -0.995 -0.549 0.264 1.624 4.127 1.259 2.824 0.488 -0.461 ms 2.609 14.04

The offset of a server in seconds. This is useful to see how the measured offset is behaving.

The chart also plots offset±rtt, where rtt is the round trip time to the server. NTP can not really know the offset of a remote chimer, NTP computes it by subtracting rtt/2 from the offset. Plotting the offset±rtt reverses this calculation to more easily see the effects of rtt changes.

Closer to 0s is better. An ideal system would be a horizontal line at 0s. Typical 90% ranges may be: local LAN server 80µs; 90% ranges for WAN server may be 4ms and much larger.

Clock Offset is field 5 in the peerstats log file. The Round Trip Time (rtt) is field 6 in the peerstats log file.



Server Offset 2606:4700:f1::1 (time.cloudflare.com)

peer offset 2606:4700:f1::1 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2606:4700:f1::1 (time.cloudflare.com) -1.150 -0.943 -0.723 0.595 0.868 1.001 1.248 1.590 1.944 0.471 0.453 ms -1.802 5.151

The offset of a server in seconds. This is useful to see how the measured offset is behaving.

The chart also plots offset±rtt, where rtt is the round trip time to the server. NTP can not really know the offset of a remote chimer, NTP computes it by subtracting rtt/2 from the offset. Plotting the offset±rtt reverses this calculation to more easily see the effects of rtt changes.

Closer to 0s is better. An ideal system would be a horizontal line at 0s. Typical 90% ranges may be: local LAN server 80µs; 90% ranges for WAN server may be 4ms and much larger.

Clock Offset is field 5 in the peerstats log file. The Round Trip Time (rtt) is field 6 in the peerstats log file.



Server Offset 2606:4700:f1::123 (time.cloudflare.com)

peer offset 2606:4700:f1::123 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2606:4700:f1::123 (time.cloudflare.com) -0.759 -0.619 -0.431 0.683 2.191 2.803 3.073 2.622 3.422 0.602 0.703 ms 1.278 8.017

The offset of a server in seconds. This is useful to see how the measured offset is behaving.

The chart also plots offset±rtt, where rtt is the round trip time to the server. NTP can not really know the offset of a remote chimer, NTP computes it by subtracting rtt/2 from the offset. Plotting the offset±rtt reverses this calculation to more easily see the effects of rtt changes.

Closer to 0s is better. An ideal system would be a horizontal line at 0s. Typical 90% ranges may be: local LAN server 80µs; 90% ranges for WAN server may be 4ms and much larger.

Clock Offset is field 5 in the peerstats log file. The Round Trip Time (rtt) is field 6 in the peerstats log file.



Server Offset SHM(0)

peer offset SHM(0) plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset SHM(0) -215.011 -145.534 -140.715 -130.312 -125.659 -123.712 -119.470 15.056 21.822 4.360 -131.042 ms -1.645 10.43

The offset of a server in seconds. This is useful to see how the measured offset is behaving.

The chart also plots offset±rtt, where rtt is the round trip time to the server. NTP can not really know the offset of a remote chimer, NTP computes it by subtracting rtt/2 from the offset. Plotting the offset±rtt reverses this calculation to more easily see the effects of rtt changes.

Closer to 0s is better. An ideal system would be a horizontal line at 0s. Typical 90% ranges may be: local LAN server 80µs; 90% ranges for WAN server may be 4ms and much larger.

Clock Offset is field 5 in the peerstats log file. The Round Trip Time (rtt) is field 6 in the peerstats log file.



Server Jitters

peer jitters plot

The RMS Jitter of all refclocks and servers. Jitter is the current estimated dispersion, in other words the variation in offset between samples.

Closer to 0s is better. An ideal system would be a horizontal line at 0s.

RMS Jitter is field 8 in the peerstats log file.



Server Jitter 2001:470:e815::24 (pi4.rellim.com)

peer jitter 2001:470:e815::24 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2001:470:e815::24 (pi4.rellim.com) 1.759 4.177 5.939 19.060 70.606 103.232 333.474 64.667 99.055 23.997 26.698 µs 3.285 25.35

The RMS Jitter of a server. Jitter is the current estimated dispersion, in other words the variation in offset between samples.

Closer to 0s is better. An ideal system would be a horizontal line at 0s.

RMS Jitter is field 8 in the peerstats log file.



Server Jitter 2001:470:e815::8 (spidey.rellim.com)

peer jitter 2001:470:e815::8 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2001:470:e815::8 (spidey.rellim.com) 1.227 3.002 4.283 15.512 55.597 102.564 302.891 51.314 99.562 19.904 21.178 µs 3.583 27.98

The RMS Jitter of a server. Jitter is the current estimated dispersion, in other words the variation in offset between samples.

Closer to 0s is better. An ideal system would be a horizontal line at 0s.

RMS Jitter is field 8 in the peerstats log file.



Server Jitter 2001:67c:1270:0:dea6:32ff:feaf:803b (khronos.mikieboy.net)

peer jitter 2001:67c:1270:0:dea6:32ff:feaf:803b plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2001:67c:1270:0:dea6:32ff:feaf:803b (khronos.mikieboy.net) 0.110 0.241 0.340 1.161 28.578 37.482 108.559 28.238 37.240 10.232 6.767 ms 1.939 8.835

The RMS Jitter of a server. Jitter is the current estimated dispersion, in other words the variation in offset between samples.

Closer to 0s is better. An ideal system would be a horizontal line at 0s.

RMS Jitter is field 8 in the peerstats log file.



Server Jitter 204.17.205.1

peer jitter 204.17.205.1 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 204.17.205.1 1.363 3.505 5.670 19.362 59.893 102.353 359.193 54.223 98.848 21.518 24.819 µs 4.292 43.22

The RMS Jitter of a server. Jitter is the current estimated dispersion, in other words the variation in offset between samples.

Closer to 0s is better. An ideal system would be a horizontal line at 0s.

RMS Jitter is field 8 in the peerstats log file.



Server Jitter 204.17.205.16

peer jitter 204.17.205.16 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 204.17.205.16 1.967 4.120 5.912 16.386 60.956 131.490 580.006 55.044 127.370 28.081 23.490 µs 7.498 100.2

The RMS Jitter of a server. Jitter is the current estimated dispersion, in other words the variation in offset between samples.

Closer to 0s is better. An ideal system would be a horizontal line at 0s.

RMS Jitter is field 8 in the peerstats log file.



Server Jitter 204.17.205.30

peer jitter 204.17.205.30 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 204.17.205.30 3.466 4.658 6.899 23.022 78.583 310.978 1,973.936 71.684 306.320 91.546 36.984 µs 12.41 192.3

The RMS Jitter of a server. Jitter is the current estimated dispersion, in other words the variation in offset between samples.

Closer to 0s is better. An ideal system would be a horizontal line at 0s.

RMS Jitter is field 8 in the peerstats log file.



Server Jitter 2405:fc00::1 (robusta.dcs1.biz)

peer jitter 2405:fc00::1 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2405:fc00::1 (robusta.dcs1.biz) 0.138 0.199 0.302 0.765 3.894 7.294 23.412 3.592 7.095 1.609 1.299 ms 6.325 73.56

The RMS Jitter of a server. Jitter is the current estimated dispersion, in other words the variation in offset between samples.

Closer to 0s is better. An ideal system would be a horizontal line at 0s.

RMS Jitter is field 8 in the peerstats log file.



Server Jitter 2604:a880:1:20::17:5001 (ntp1.glypnod.com)

peer jitter 2604:a880:1:20::17:5001 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2604:a880:1:20::17:5001 (ntp1.glypnod.com) 0.117 0.190 0.274 0.603 2.233 5.544 43.721 1.958 5.354 1.873 0.959 ms 14.59 283.4

The RMS Jitter of a server. Jitter is the current estimated dispersion, in other words the variation in offset between samples.

Closer to 0s is better. An ideal system would be a horizontal line at 0s.

RMS Jitter is field 8 in the peerstats log file.



Server Jitter 2606:4700:f1::1 (time.cloudflare.com)

peer jitter 2606:4700:f1::1 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2606:4700:f1::1 (time.cloudflare.com) 0.131 0.205 0.248 0.494 1.380 2.566 9.600 1.132 2.361 0.628 0.617 ms 9.254 122.5

The RMS Jitter of a server. Jitter is the current estimated dispersion, in other words the variation in offset between samples.

Closer to 0s is better. An ideal system would be a horizontal line at 0s.

RMS Jitter is field 8 in the peerstats log file.



Server Jitter 2606:4700:f1::123 (time.cloudflare.com)

peer jitter 2606:4700:f1::123 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2606:4700:f1::123 (time.cloudflare.com) 0.111 0.170 0.239 0.500 1.437 3.740 137.636 1.198 3.570 6.954 1.048 ms 18.47 358.4

The RMS Jitter of a server. Jitter is the current estimated dispersion, in other words the variation in offset between samples.

Closer to 0s is better. An ideal system would be a horizontal line at 0s.

RMS Jitter is field 8 in the peerstats log file.



Server Jitter SHM(0)

peer jitter SHM(0) plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter SHM(0) 0.104 0.291 0.418 1.132 8.288 11.212 71.000 7.871 10.921 2.684 2.227 ms 3.069 26.62

The RMS Jitter of a server. Jitter is the current estimated dispersion, in other words the variation in offset between samples.

Closer to 0s is better. An ideal system would be a horizontal line at 0s.

RMS Jitter is field 8 in the peerstats log file.



Summary


Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Local Clock Frequency Offset 11.426 11.503 11.548 11.944 13.595 13.760 13.963 2.047 2.257 0.482 12.023 ppm 2.398 8.986
Local Clock Time Offset -428.997 -119.659 -47.048 -2.431 43.492 109.040 601.468 90.540 228.699 46.150 -2.078 µs 0.8697 42.31
Local RMS Frequency Jitter 3.657 5.073 6.266 12.109 45.694 133.990 238.733 39.428 128.917 21.253 17.491 ppb 4.973 32.55
Local RMS Time Jitter 7.787 10.505 12.599 21.403 44.106 74.698 134.781 31.507 64.194 11.811 23.778 µs 3.213 19.22
Server Jitter 2001:470:e815::24 (pi4.rellim.com) 1.759 4.177 5.939 19.060 70.606 103.232 333.474 64.667 99.055 23.997 26.698 µs 3.285 25.35
Server Jitter 2001:470:e815::8 (spidey.rellim.com) 1.227 3.002 4.283 15.512 55.597 102.564 302.891 51.314 99.562 19.904 21.178 µs 3.583 27.98
Server Jitter 2001:67c:1270:0:dea6:32ff:feaf:803b (khronos.mikieboy.net) 0.110 0.241 0.340 1.161 28.578 37.482 108.559 28.238 37.240 10.232 6.767 ms 1.939 8.835
Server Jitter 204.17.205.1 1.363 3.505 5.670 19.362 59.893 102.353 359.193 54.223 98.848 21.518 24.819 µs 4.292 43.22
Server Jitter 204.17.205.16 1.967 4.120 5.912 16.386 60.956 131.490 580.006 55.044 127.370 28.081 23.490 µs 7.498 100.2
Server Jitter 204.17.205.30 3.466 4.658 6.899 23.022 78.583 310.978 1,973.936 71.684 306.320 91.546 36.984 µs 12.41 192.3
Server Jitter 2405:fc00::1 (robusta.dcs1.biz) 0.138 0.199 0.302 0.765 3.894 7.294 23.412 3.592 7.095 1.609 1.299 ms 6.325 73.56
Server Jitter 2604:a880:1:20::17:5001 (ntp1.glypnod.com) 0.117 0.190 0.274 0.603 2.233 5.544 43.721 1.958 5.354 1.873 0.959 ms 14.59 283.4
Server Jitter 2606:4700:f1::1 (time.cloudflare.com) 0.131 0.205 0.248 0.494 1.380 2.566 9.600 1.132 2.361 0.628 0.617 ms 9.254 122.5
Server Jitter 2606:4700:f1::123 (time.cloudflare.com) 0.111 0.170 0.239 0.500 1.437 3.740 137.636 1.198 3.570 6.954 1.048 ms 18.47 358.4
Server Jitter SHM(0) 0.104 0.291 0.418 1.132 8.288 11.212 71.000 7.871 10.921 2.684 2.227 ms 3.069 26.62
Server Offset 2001:470:e815::24 (pi4.rellim.com) -475.291 -133.833 -61.247 8.801 83.626 158.980 624.705 144.873 292.813 59.175 10.477 µs 0.9254 26.98
Server Offset 2001:470:e815::8 (spidey.rellim.com) -1,093.232 -896.159 -658.425 -2.587 311.385 473.061 750.773 969.810 1,369.220 283.484 -47.718 µs -1.08 4.336
Server Offset 2001:67c:1270:0:dea6:32ff:feaf:803b (khronos.mikieboy.net) -16.541 -0.834 -0.417 -0.073 0.404 2.014 2.505 0.821 2.848 0.579 -0.038 ms -11.72 353.3
Server Offset 204.17.205.1 -1.682 -1.435 -1.039 0.021 0.502 0.664 1.086 1.541 2.099 0.423 -0.040 ms -1.311 5.262
Server Offset 204.17.205.16 -584.029 -138.393 -51.983 11.282 72.957 154.442 735.280 124.941 292.835 56.127 10.577 µs 0.1329 36.49
Server Offset 204.17.205.30 -479.202 -167.723 -99.239 -18.323 48.535 109.556 542.357 147.774 277.280 57.784 -20.182 µs 0.7856 25.62
Server Offset 2405:fc00::1 (robusta.dcs1.biz) -0.466 0.178 2.189 4.329 5.009 5.199 5.658 2.820 5.020 1.011 3.973 ms -1.454 4.973
Server Offset 2604:a880:1:20::17:5001 (ntp1.glypnod.com) -1.441 -1.201 -0.995 -0.549 0.264 1.624 4.127 1.259 2.824 0.488 -0.461 ms 2.609 14.04
Server Offset 2606:4700:f1::1 (time.cloudflare.com) -1.150 -0.943 -0.723 0.595 0.868 1.001 1.248 1.590 1.944 0.471 0.453 ms -1.802 5.151
Server Offset 2606:4700:f1::123 (time.cloudflare.com) -0.759 -0.619 -0.431 0.683 2.191 2.803 3.073 2.622 3.422 0.602 0.703 ms 1.278 8.017
Server Offset SHM(0) -215.011 -145.534 -140.715 -130.312 -125.659 -123.712 -119.470 15.056 21.822 4.360 -131.042 ms -1.645 10.43
TDOP 0.710 0.850 0.940 1.380 2.460 3.610 26.900 1.520 2.760 0.559 1.497 4.079 66.89
Temp /dev/sda 42.000 44.000 44.000 47.000 49.000 50.000 51.000 5.000 6.000 1.540 46.583 °C
Temp /dev/sdb 32.000 33.000 34.000 36.000 38.000 39.000 40.000 4.000 6.000 1.416 35.699 °C
Temp LM0 48.000 49.000 49.000 54.000 58.000 59.000 60.000 9.000 10.000 2.784 53.765 °C
Temp LM1 38.250 39.875 42.375 45.875 72.125 74.609 77.750 29.750 34.734 7.232 47.540 °C
Temp LM10 25.000 25.000 25.000 25.000 25.000 25.870 26.000 0.000 0.870 0.102 25.010 °C
Temp LM11 60.000 61.000 61.000 62.000 63.000 64.000 65.000 2.000 3.000 0.778 62.313 °C
Temp LM12 2.000 3.000 5.000 13.000 21.000 23.000 24.000 16.000 20.000 4.601 13.195 °C
Temp LM13 25.000 25.000 25.000 25.000 25.000 25.000 26.000 0.000 0.000 0.097 25.009 °C
Temp LM14 41.000 42.000 42.000 44.000 45.000 46.000 46.000 3.000 4.000 0.911 43.662 °C
Temp LM15 33.000 34.000 35.000 37.000 61.000 63.000 66.000 26.000 29.000 6.324 38.662 °C
Temp LM16 65.500 66.500 66.500 67.500 68.500 69.000 69.500 2.000 2.500 0.583 67.588 °C
Temp LM17 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 °C
Temp LM18 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 °C
Temp LM19 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 °C
Temp LM2 38.250 40.000 41.250 43.500 71.250 74.000 80.750 30.000 34.000 7.652 46.242 °C
Temp LM20 38.250 39.750 42.375 45.750 72.169 74.500 77.500 29.794 34.750 7.230 47.512 °C
Temp LM21 65.625 66.500 66.750 67.750 68.750 69.000 69.500 2.000 2.500 0.561 67.722 °C
Temp LM22 32.000 33.000 34.000 36.000 38.000 39.000 40.000 4.000 6.000 1.380 35.733 °C
Temp LM23 63.850 64.850 64.850 67.850 69.850 69.850 70.850 5.000 5.000 1.505 67.922 °C
Temp LM3 42.000 44.000 44.000 47.000 49.000 50.000 51.000 5.000 6.000 1.537 46.598 °C
Temp LM4 46.850 47.850 48.850 49.850 50.850 52.850 54.850 2.000 5.000 1.053 50.086 °C
Temp LM5 46.850 47.850 48.850 49.850 50.850 52.850 54.850 2.000 5.000 1.062 50.098 °C
Temp LM6 54.850 55.850 56.850 57.850 60.850 66.850 72.850 4.000 11.000 1.888 58.448 °C
Temp LM7 46.850 47.850 48.850 49.850 50.850 52.850 54.850 2.000 5.000 1.053 50.105 °C
Temp LM8 41.000 42.000 42.000 44.000 45.000 46.000 46.000 3.000 4.000 0.912 43.663 °C
Temp LM9 33.000 34.500 35.500 37.500 50.000 51.500 52.000 14.500 17.000 3.418 38.028 °C
nSats 4.000 7.000 8.000 11.000 14.000 15.000 17.000 6.000 8.000 1.682 11.006 nSat -0.1371 3.06
Summary as CSV file


This server:

Motherboard:
OS: Gentoo unstable
GPS:
GPS/PPS server: gpsd
NTP server: NTPsec
../ntp.conf

Notes:

Feb 21 03:28:57 UTC 2019: New install

Glossary:

frequency offset:
The difference between the ntpd calculated frequency and the local system clock frequency (usually in parts per million, ppm)
jitter, dispersion:
The short term change in a value. NTP measures Local Time Jitter, Refclock Jitter, and Server Jitter in seconds. Local Frequency Jitter is in ppm or ppb.
Kurtosis, Kurt:
The kurtosis of a random variable X is the fourth standardized moment and is a dimension-less ratio. ntpviz uses standard Kurtosis. There are other different ways to calculate Kurtosis.
A normal distribution has a Kurtosis of three. NIST describes a kurtosis over three as "heavy tailed" and one under three as "light tailed". See [NIST1]
ms, millisecond:
One thousandth of a second = 0.001 seconds, 1e-3 seconds
mu, mean:
The arithmetic mean: the sum of all the values divided by the number of values. The formula for mu is: "mu = (∑xi) / N". Where xi denotes the data points and N is the number of data points.
ns, nanosecond:
One billionth of a second, also one thousandth of a microsecond, 0.000000001 seconds and 1e-9 seconds.
percentile:
The value below which a given percentage of values fall. See [NIST2]
ppb, parts per billion:
Ratio between two values. These following are all the same: 1 ppb, one in one billion, 1/1,000,000,000, 0.000,000,001, 1e-9 and 0.000,000,1%
ppm, parts per million:
Ratio between two values. These following are all the same: 1 ppm, one in one million, 1/1,000,000, 0.000,001, and 0.000,1%
‰, parts per thousand:
Ratio between two values. These following are all the same: 1 ‰. one in one thousand, 1/1,000, 0.001, and 0.1%
refclock:
Reference clock, a local GPS module or other local source of time.
remote clock:
Any clock reached over the network, LAN or WAN. Also called a peer or server.
σ, sigma:
Sigma denotes the standard deviation (SD) and is centered on the arithmetic mean of the data set. The SD is simply the square root of the variance of the data set. Two sigma is simply twice the standard deviation. Three sigma is three times sigma. Smaller is better.
The formula for sigma is: "σ = √[ ∑(xi-mu)^2 / N ]". Where xi denotes the data points and N is the number of data points.
Skewness, Skew:
The skewness of a random variable X is the third standardized moment and is a dimension-less ratio. ntpviz uses the Fisher-Pearson moment of skewness. See [NIST1]. There are other different ways to calculate Skewness.
Some have said: "The qualitative interpretation of the skew is complicated and unintuitive".
A normal distribution has a skewness of zero.
time offset:
The difference between the ntpd calculated time and the local system clock's time. Also called phase offset.
upstream clock:
Any server or reference clock used as a source of time.
µs, us, microsecond:
One millionth of a second, also one thousandth of a millisecond, 0.000,001 seconds, and 1e-6 seconds.

References:

[NIST1]: NIST/SEMATECH e-Handbook of Statistical Methods, 2012
1.3.5.11. Measures of Skewness and Kurtosis
https://www.itl.nist.gov/div898/handbook/eda/section3/eda35b.htm
[NIST]}: NIST/SEMATECH e-Handbook of Statistical Methods, 2012
7.2.6.2. Percentiles
https://www.itl.nist.gov/div898/handbook/prc/section2/prc262.htm


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