NTPsec

Kong

Report generated: Sun Feb 23 04:49:00 2025 UTC
Start Time: Sat Feb 22 04:49:00 2025 UTC
End Time: Sun Feb 23 04:49:00 2025 UTC
Report Period: 1.0 days
Warning: plots clipped

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 -461.211 -320.517 -73.783 -5.906 46.298 113.916 367.617 120.082 434.433 59.709 -9.462 µs -2.132 26.23
Local Clock Frequency Offset 11.436 11.449 11.518 11.626 12.265 13.049 13.776 0.747 1.599 0.308 11.734 ppm 3.431 17.82

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 9.797 10.916 12.910 23.984 70.003 105.002 122.635 57.093 94.086 18.226 28.392 µs 2.827 11.68

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 4.378 5.251 5.974 11.563 81.857 139.325 173.266 75.883 134.074 26.334 20.089 ppb 3.321 14.42

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 -461.211 -320.517 -73.783 -5.906 46.298 113.916 367.617 120.082 434.433 59.709 -9.462 µs -2.132 26.23

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 11.436 11.449 11.518 11.626 12.265 13.049 13.776 0.747 1.599 0.308 11.734 ppm 3.431 17.82
Temp /dev/sda 45.000 45.000 46.000 47.000 50.000 50.000 51.000 4.000 5.000 1.274 47.406 °C
Temp /dev/sdb 33.000 33.000 33.000 35.000 38.000 38.000 38.000 5.000 5.000 1.339 35.094 °C
Temp LM0 48.000 49.000 50.000 55.000 58.000 58.000 59.000 8.000 9.000 2.533 54.705 °C
Temp LM1 38.500 39.326 40.375 41.625 48.831 65.442 83.875 8.456 26.116 4.541 42.650 °C
Temp LM10 25.000 25.000 25.000 25.000 25.000 25.000 26.000 0.000 0.000 0.059 25.003 °C
Temp LM11 61.000 61.870 62.000 62.000 63.000 63.000 63.000 1.000 1.130 0.515 62.427 °C
Temp LM12 4.000 4.000 7.000 14.000 22.000 25.000 27.000 15.000 21.000 4.412 14.326 °C
Temp LM13 25.000 25.000 25.000 25.000 25.000 25.000 26.000 0.000 0.000 0.059 25.003 °C
Temp LM14 42.000 43.000 44.000 44.000 45.000 45.000 45.000 1.000 2.000 0.310 44.035 °C
Temp LM15 34.000 34.000 35.000 36.000 39.000 53.780 72.000 4.000 19.780 3.525 36.337 °C
Temp LM16 66.500 67.000 67.500 68.000 68.000 68.500 68.500 0.500 1.500 0.311 67.799 °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 39.000 40.500 42.250 47.500 66.247 83.500 7.000 27.247 4.318 43.099 °C
Temp LM20 38.500 39.326 40.375 41.625 48.831 65.285 83.875 8.456 25.959 4.532 42.643 °C
Temp LM21 66.500 67.109 67.500 68.000 68.250 68.500 68.750 0.750 1.391 0.265 67.923 °C
Temp LM22 33.000 33.000 34.000 35.000 38.000 38.000 38.000 4.000 5.000 1.221 35.174 °C
Temp LM23 63.850 64.850 67.850 69.850 70.850 70.850 72.850 3.000 6.000 1.205 69.996 °C
Temp LM3 45.000 45.000 46.000 48.000 50.000 50.000 51.000 4.000 5.000 1.276 47.438 °C
Temp LM4 48.850 48.850 49.850 50.850 51.850 52.850 55.850 2.000 4.000 0.629 50.829 °C
Temp LM5 48.850 48.850 49.850 50.850 51.850 52.850 55.850 2.000 4.000 0.626 50.826 °C
Temp LM6 56.850 56.850 57.850 58.850 61.850 66.110 73.850 4.000 9.260 1.689 59.468 °C
Temp LM7 48.850 48.850 49.850 50.850 51.850 52.850 55.850 2.000 4.000 0.607 50.836 °C
Temp LM8 43.000 43.000 44.000 44.000 45.000 45.000 45.000 1.000 2.000 0.292 44.038 °C
Temp LM9 34.000 34.500 35.000 36.000 39.000 43.065 52.500 4.000 8.565 1.664 36.311 °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 4.000 5.000 7.000 10.000 11.000 11.000 5.000 7.000 1.486 7.136 nSat 0.03568 2.807
TDOP 0.830 1.000 1.130 2.230 6.720 17.930 127.250 5.590 16.930 5.166 3.136 12.06 191.5

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) -527.887 -383.171 -70.936 16.562 100.766 165.311 483.179 171.702 548.482 77.777 12.465 µs -2.159 22.57

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) -1.339 -1.199 -0.762 -0.034 0.701 0.808 0.858 1.464 2.008 0.417 -0.072 ms -0.3565 3.261

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) -1.326 -1.274 -1.117 -0.831 -0.522 -0.354 0.551 0.595 0.920 0.195 -0.823 ms 1.217 11.05

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 -1.274 -1.235 -1.083 0.018 1.181 1.341 1.361 2.264 2.576 0.571 0.031 ms 0.09858 3.5

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 -484.037 -222.913 -103.209 -34.061 11.552 115.294 330.299 114.760 338.207 56.474 -37.351 µs -1.401 26.26

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) -21.588 -21.158 -20.558 0.091 0.795 2.871 15.755 21.353 24.029 6.592 -2.645 ms -1.789 5.168

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) -1,243.216 -936.884 -749.260 -347.988 134.575 361.661 771.868 883.835 1,298.545 286.433 -338.094 µs 0.3495 3.753

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) -137.245 -129.754 -99.791 349.106 610.933 654.455 665.336 710.724 784.210 252.401 305.627 µs -0.3366 1.847

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) 0.231 0.268 0.357 0.561 0.812 1.023 1.304 0.456 0.755 0.148 0.571 ms 0.7498 5.089

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) -167.396 -130.973 -129.709 -125.495 -121.319 -120.240 -119.073 8.390 10.733 2.698 -125.504 ms -1.3 17.17

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) 1.883 3.155 5.586 19.888 88.437 155.376 298.635 82.851 152.221 32.114 29.603 µs 3.556 22.66

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) 2.211 3.222 4.645 16.418 56.846 125.640 252.380 52.201 122.418 24.326 22.193 µs 4.342 29.74

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) 0.115 0.167 0.247 0.568 2.807 13.136 34.683 2.560 12.970 3.282 1.228 ms 8.25 79.62

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.



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 3.032 4.103 5.293 21.386 88.290 131.136 297.049 82.997 127.033 30.483 28.991 µs 3.923 26.13

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 4.502 5.762 7.792 21.217 119.851 278.400 472.330 112.059 272.638 53.523 37.716 µs 4.512 28.93

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) 0.135 0.231 0.280 0.785 7.131 13.311 30.114 6.851 13.080 3.124 2.053 ms 4.064 27.92

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) 0.132 0.156 0.224 0.567 1.638 9.461 64.126 1.414 9.305 5.493 1.219 ms 10.99 125.1

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) 0.201 0.209 0.239 0.514 3.166 3.395 3.453 2.927 3.187 1.035 0.933 ms 1.69 4.152

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) 0.154 0.181 0.250 0.499 2.660 12.104 12.174 2.410 11.924 1.615 0.888 ms 5.7 38.11

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) 0.126 0.255 0.373 0.929 2.430 6.932 35.446 2.057 6.678 1.348 1.198 ms 9.147 141.7

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 11.436 11.449 11.518 11.626 12.265 13.049 13.776 0.747 1.599 0.308 11.734 ppm 3.431 17.82
Local Clock Time Offset -461.211 -320.517 -73.783 -5.906 46.298 113.916 367.617 120.082 434.433 59.709 -9.462 µs -2.132 26.23
Local RMS Frequency Jitter 4.378 5.251 5.974 11.563 81.857 139.325 173.266 75.883 134.074 26.334 20.089 ppb 3.321 14.42
Local RMS Time Jitter 9.797 10.916 12.910 23.984 70.003 105.002 122.635 57.093 94.086 18.226 28.392 µs 2.827 11.68
Server Jitter 2001:470:e815::24 (pi4.rellim.com) 1.883 3.155 5.586 19.888 88.437 155.376 298.635 82.851 152.221 32.114 29.603 µs 3.556 22.66
Server Jitter 2001:470:e815::8 (spidey.rellim.com) 2.211 3.222 4.645 16.418 56.846 125.640 252.380 52.201 122.418 24.326 22.193 µs 4.342 29.74
Server Jitter 2001:67c:1270:0:dea6:32ff:feaf:803b (khronos.mikieboy.net) 0.115 0.167 0.247 0.568 2.807 13.136 34.683 2.560 12.970 3.282 1.228 ms 8.25 79.62
Server Jitter 204.17.205.1 3.032 4.103 5.293 21.386 88.290 131.136 297.049 82.997 127.033 30.483 28.991 µs 3.923 26.13
Server Jitter 204.17.205.30 4.502 5.762 7.792 21.217 119.851 278.400 472.330 112.059 272.638 53.523 37.716 µs 4.512 28.93
Server Jitter 2405:fc00::1 (robusta.dcs1.biz) 0.135 0.231 0.280 0.785 7.131 13.311 30.114 6.851 13.080 3.124 2.053 ms 4.064 27.92
Server Jitter 2604:a880:1:20::17:5001 (ntp1.glypnod.com) 0.132 0.156 0.224 0.567 1.638 9.461 64.126 1.414 9.305 5.493 1.219 ms 10.99 125.1
Server Jitter 2606:4700:f1::1 (time.cloudflare.com) 0.201 0.209 0.239 0.514 3.166 3.395 3.453 2.927 3.187 1.035 0.933 ms 1.69 4.152
Server Jitter 2606:4700:f1::123 (time.cloudflare.com) 0.154 0.181 0.250 0.499 2.660 12.104 12.174 2.410 11.924 1.615 0.888 ms 5.7 38.11
Server Jitter SHM(0) 0.126 0.255 0.373 0.929 2.430 6.932 35.446 2.057 6.678 1.348 1.198 ms 9.147 141.7
Server Offset 2001:470:e815::24 (pi4.rellim.com) -527.887 -383.171 -70.936 16.562 100.766 165.311 483.179 171.702 548.482 77.777 12.465 µs -2.159 22.57
Server Offset 2001:470:e815::8 (spidey.rellim.com) -1.339 -1.199 -0.762 -0.034 0.701 0.808 0.858 1.464 2.008 0.417 -0.072 ms -0.3565 3.261
Server Offset 2001:67c:1270:0:dea6:32ff:feaf:803b (khronos.mikieboy.net) -1.326 -1.274 -1.117 -0.831 -0.522 -0.354 0.551 0.595 0.920 0.195 -0.823 ms 1.217 11.05
Server Offset 204.17.205.1 -1.274 -1.235 -1.083 0.018 1.181 1.341 1.361 2.264 2.576 0.571 0.031 ms 0.09858 3.5
Server Offset 204.17.205.30 -484.037 -222.913 -103.209 -34.061 11.552 115.294 330.299 114.760 338.207 56.474 -37.351 µs -1.401 26.26
Server Offset 2405:fc00::1 (robusta.dcs1.biz) -21.588 -21.158 -20.558 0.091 0.795 2.871 15.755 21.353 24.029 6.592 -2.645 ms -1.789 5.168
Server Offset 2604:a880:1:20::17:5001 (ntp1.glypnod.com) -1,243.216 -936.884 -749.260 -347.988 134.575 361.661 771.868 883.835 1,298.545 286.433 -338.094 µs 0.3495 3.753
Server Offset 2606:4700:f1::1 (time.cloudflare.com) -137.245 -129.754 -99.791 349.106 610.933 654.455 665.336 710.724 784.210 252.401 305.627 µs -0.3366 1.847
Server Offset 2606:4700:f1::123 (time.cloudflare.com) 0.231 0.268 0.357 0.561 0.812 1.023 1.304 0.456 0.755 0.148 0.571 ms 0.7498 5.089
Server Offset SHM(0) -167.396 -130.973 -129.709 -125.495 -121.319 -120.240 -119.073 8.390 10.733 2.698 -125.504 ms -1.3 17.17
TDOP 0.830 1.000 1.130 2.230 6.720 17.930 127.250 5.590 16.930 5.166 3.136 12.06 191.5
Temp /dev/sda 45.000 45.000 46.000 47.000 50.000 50.000 51.000 4.000 5.000 1.274 47.406 °C
Temp /dev/sdb 33.000 33.000 33.000 35.000 38.000 38.000 38.000 5.000 5.000 1.339 35.094 °C
Temp LM0 48.000 49.000 50.000 55.000 58.000 58.000 59.000 8.000 9.000 2.533 54.705 °C
Temp LM1 38.500 39.326 40.375 41.625 48.831 65.442 83.875 8.456 26.116 4.541 42.650 °C
Temp LM10 25.000 25.000 25.000 25.000 25.000 25.000 26.000 0.000 0.000 0.059 25.003 °C
Temp LM11 61.000 61.870 62.000 62.000 63.000 63.000 63.000 1.000 1.130 0.515 62.427 °C
Temp LM12 4.000 4.000 7.000 14.000 22.000 25.000 27.000 15.000 21.000 4.412 14.326 °C
Temp LM13 25.000 25.000 25.000 25.000 25.000 25.000 26.000 0.000 0.000 0.059 25.003 °C
Temp LM14 42.000 43.000 44.000 44.000 45.000 45.000 45.000 1.000 2.000 0.310 44.035 °C
Temp LM15 34.000 34.000 35.000 36.000 39.000 53.780 72.000 4.000 19.780 3.525 36.337 °C
Temp LM16 66.500 67.000 67.500 68.000 68.000 68.500 68.500 0.500 1.500 0.311 67.799 °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 39.000 40.500 42.250 47.500 66.247 83.500 7.000 27.247 4.318 43.099 °C
Temp LM20 38.500 39.326 40.375 41.625 48.831 65.285 83.875 8.456 25.959 4.532 42.643 °C
Temp LM21 66.500 67.109 67.500 68.000 68.250 68.500 68.750 0.750 1.391 0.265 67.923 °C
Temp LM22 33.000 33.000 34.000 35.000 38.000 38.000 38.000 4.000 5.000 1.221 35.174 °C
Temp LM23 63.850 64.850 67.850 69.850 70.850 70.850 72.850 3.000 6.000 1.205 69.996 °C
Temp LM3 45.000 45.000 46.000 48.000 50.000 50.000 51.000 4.000 5.000 1.276 47.438 °C
Temp LM4 48.850 48.850 49.850 50.850 51.850 52.850 55.850 2.000 4.000 0.629 50.829 °C
Temp LM5 48.850 48.850 49.850 50.850 51.850 52.850 55.850 2.000 4.000 0.626 50.826 °C
Temp LM6 56.850 56.850 57.850 58.850 61.850 66.110 73.850 4.000 9.260 1.689 59.468 °C
Temp LM7 48.850 48.850 49.850 50.850 51.850 52.850 55.850 2.000 4.000 0.607 50.836 °C
Temp LM8 43.000 43.000 44.000 44.000 45.000 45.000 45.000 1.000 2.000 0.292 44.038 °C
Temp LM9 34.000 34.500 35.000 36.000 39.000 43.065 52.500 4.000 8.565 1.664 36.311 °C
nSats 4.000 4.000 5.000 7.000 10.000 11.000 11.000 5.000 7.000 1.486 7.136 nSat 0.03568 2.807
Summary as CSV file


This server:

Motherboard:
OS: Gentoo unstable
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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