NTPsec

Kong

Report generated: Sat Jan 18 00:49:00 2025 UTC
Start Time: Fri Jan 17 00:49:00 2025 UTC
End Time: Sat Jan 18 00:49:00 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 -392.600 -214.532 -47.934 -3.303 36.502 52.621 58.274 84.436 267.153 41.769 -7.340 µs -4.631 35.79
Local Clock Frequency Offset 11.638 11.682 11.752 12.095 13.921 13.941 13.965 2.169 2.259 0.780 12.370 ppm 1.351 3.071

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 12.059 13.710 15.318 21.636 34.495 58.059 70.701 19.178 44.349 7.800 23.358 µs 2.654 13.29

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 4.982 5.686 6.558 12.320 35.588 115.238 131.588 29.029 109.552 17.082 16.527 ppb 4.499 25

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 -392.600 -214.532 -47.934 -3.303 36.502 52.621 58.274 84.436 267.153 41.769 -7.340 µs -4.631 35.79

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 11.638 11.682 11.752 12.095 13.921 13.941 13.965 2.169 2.259 0.780 12.370 ppm 1.351 3.071
Temp /dev/sda 44.000 45.000 45.000 47.000 49.000 49.000 49.000 4.000 4.000 1.512 46.872 °C
Temp /dev/sdb 34.000 34.000 34.000 36.000 38.000 38.000 38.000 4.000 4.000 1.219 36.083 °C
Temp LM0 47.000 48.000 49.000 53.000 58.000 59.000 59.000 9.000 11.000 2.887 53.236 °C
Temp LM1 44.250 44.484 44.750 47.625 74.831 76.157 77.500 30.081 31.674 10.849 52.589 °C
Temp LM10 25.000 25.000 25.000 25.000 25.000 25.130 26.000 0.000 0.130 0.102 25.010 °C
Temp LM11 61.000 61.000 62.000 63.000 64.000 64.000 64.000 2.000 3.000 0.801 62.896 °C
Temp LM12 3.000 3.000 5.000 12.000 20.000 23.000 24.000 15.000 20.000 4.645 12.608 °C
Temp LM13 25.000 25.000 25.000 25.000 25.000 26.000 26.000 0.000 1.000 0.117 25.014 °C
Temp LM14 43.000 43.000 43.000 44.000 46.000 46.000 46.000 3.000 3.000 0.954 44.295 °C
Temp LM15 35.000 36.000 36.000 38.000 63.000 65.000 66.000 27.000 29.000 10.042 42.597 °C
Temp LM16 66.500 66.935 67.000 68.000 69.000 69.000 69.000 2.000 2.065 0.592 68.083 °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 41.000 42.250 42.500 44.125 74.162 77.630 79.500 31.662 35.380 11.748 50.291 °C
Temp LM20 44.250 44.500 44.750 47.625 74.875 76.141 77.625 30.125 31.641 10.881 52.498 °C
Temp LM21 66.750 66.968 67.250 68.000 69.000 69.000 69.000 1.750 2.032 0.575 68.206 °C
Temp LM22 34.000 34.000 35.000 36.000 38.000 38.000 38.000 3.000 4.000 1.141 36.205 °C
Temp LM23 64.850 64.850 64.850 67.850 69.850 69.850 70.850 5.000 5.000 1.529 67.787 °C
Temp LM3 44.000 45.000 45.000 47.000 49.000 49.000 49.000 4.000 4.000 1.512 46.889 °C
Temp LM4 48.850 48.850 48.850 50.850 52.850 54.850 55.850 4.000 6.000 1.212 50.524 °C
Temp LM5 48.850 48.850 48.850 50.850 52.850 54.850 55.850 4.000 6.000 1.192 50.524 °C
Temp LM6 54.850 56.850 56.850 58.850 63.850 69.980 73.850 7.000 13.130 2.609 59.333 °C
Temp LM7 48.850 48.850 48.850 50.850 52.850 54.850 55.850 4.000 6.000 1.176 50.534 °C
Temp LM8 43.000 43.000 43.000 44.000 46.000 46.000 46.000 3.000 3.000 0.962 44.302 °C
Temp LM9 36.000 36.500 36.500 38.000 52.000 52.500 52.500 15.500 16.000 5.622 40.361 °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 6.000 8.000 9.000 12.000 14.000 15.000 16.000 5.000 7.000 1.401 11.532 nSat -0.001175 2.89
TDOP 0.700 0.820 0.920 1.270 2.180 3.230 6.330 1.260 2.410 0.442 1.375 2.509 14.54

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) -403.108 -194.880 -61.531 6.148 72.002 102.294 115.288 133.533 297.173 50.291 2.285 µs -2.549 18.44

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) -967.993 -945.599 -848.299 45.885 699.299 786.118 843.263 1,547.598 1,731.717 401.887 31.646 µs -0.4282 3.165

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) -893.194 -695.447 -335.090 -114.816 174.502 391.926 1,307.648 509.591 1,087.373 197.771 -95.487 µs 1.057 12.76

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 -1.167 -1.151 -0.970 0.040 0.436 0.468 0.499 1.405 1.619 0.365 -0.013 ms -1.561 5.386

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 -293.704 -170.578 -70.096 13.144 62.728 84.090 107.278 132.824 254.668 44.255 6.814 µs -2.097 11.74

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 -405.228 -240.007 -95.032 -16.514 38.656 62.416 79.914 133.688 302.423 52.807 -22.104 µs -3.291 21.54

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) 1.277 1.377 1.485 1.845 2.250 2.471 2.604 0.765 1.094 0.241 1.851 ms 0.2739 2.867

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) -1.070 -1.003 -0.945 -0.608 -0.172 -0.046 0.110 0.773 0.957 0.224 -0.592 ms 0.4661 3.056

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) 195.977 279.603 372.392 547.363 753.743 826.478 935.293 381.351 546.875 120.135 553.535 µs 0.09414 3.001

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) 382.657 389.657 417.658 525.333 886.302 938.300 951.299 468.644 548.642 175.035 602.366 µs 0.7647 2.451

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) -150.933 -136.737 -134.870 -130.539 -126.815 -125.736 -123.752 8.055 11.001 2.500 -130.658 ms -0.5951 4.99

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) 2.868 4.128 5.582 16.993 68.755 85.711 118.182 63.173 81.583 19.982 24.580 µs 1.465 4.779

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) 2.043 2.768 4.299 16.620 50.616 71.172 136.388 46.317 68.404 16.113 20.696 µs 2.034 10.3

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 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) 0.103 0.181 0.311 0.896 27.135 34.916 37.586 26.825 34.735 9.867 6.382 ms 1.516 3.912

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 1.684 2.620 4.582 16.055 50.514 78.268 122.569 45.932 75.648 15.947 20.897 µs 2.06 9.926

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 4.284 4.723 6.201 15.471 56.367 91.022 122.312 50.167 86.299 18.385 21.662 µs 2.288 8.992

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 2.683 3.778 5.956 20.018 70.215 103.662 181.045 64.259 99.885 22.263 26.499 µs 2.457 13.04

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) 0.150 0.209 0.276 0.671 3.927 9.224 45.198 3.652 9.015 3.175 1.413 ms 9.963 128

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) 0.164 0.191 0.287 0.545 2.206 3.091 4.492 1.920 2.901 0.646 0.778 ms 2.683 12.02

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) 0.126 0.163 0.239 0.445 1.208 2.222 8.381 0.968 2.059 0.700 0.602 ms 8.11 82.26

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) 0.280 0.291 0.338 0.651 5.888 6.127 6.186 5.550 5.835 2.489 2.412 ms 0.5428 1.35

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 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) 0.099 0.289 0.409 0.989 2.478 4.360 18.595 2.068 4.071 0.947 1.195 ms 6.422 84.12

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 11.638 11.682 11.752 12.095 13.921 13.941 13.965 2.169 2.259 0.780 12.370 ppm 1.351 3.071
Local Clock Time Offset -392.600 -214.532 -47.934 -3.303 36.502 52.621 58.274 84.436 267.153 41.769 -7.340 µs -4.631 35.79
Local RMS Frequency Jitter 4.982 5.686 6.558 12.320 35.588 115.238 131.588 29.029 109.552 17.082 16.527 ppb 4.499 25
Local RMS Time Jitter 12.059 13.710 15.318 21.636 34.495 58.059 70.701 19.178 44.349 7.800 23.358 µs 2.654 13.29
Server Jitter 2001:470:e815::24 (pi4.rellim.com) 2.868 4.128 5.582 16.993 68.755 85.711 118.182 63.173 81.583 19.982 24.580 µs 1.465 4.779
Server Jitter 2001:470:e815::8 (spidey.rellim.com) 2.043 2.768 4.299 16.620 50.616 71.172 136.388 46.317 68.404 16.113 20.696 µs 2.034 10.3
Server Jitter 2001:67c:1270:0:dea6:32ff:feaf:803b (khronos.mikieboy.net) 0.103 0.181 0.311 0.896 27.135 34.916 37.586 26.825 34.735 9.867 6.382 ms 1.516 3.912
Server Jitter 204.17.205.1 1.684 2.620 4.582 16.055 50.514 78.268 122.569 45.932 75.648 15.947 20.897 µs 2.06 9.926
Server Jitter 204.17.205.16 4.284 4.723 6.201 15.471 56.367 91.022 122.312 50.167 86.299 18.385 21.662 µs 2.288 8.992
Server Jitter 204.17.205.30 2.683 3.778 5.956 20.018 70.215 103.662 181.045 64.259 99.885 22.263 26.499 µs 2.457 13.04
Server Jitter 2405:fc00::1 (robusta.dcs1.biz) 0.150 0.209 0.276 0.671 3.927 9.224 45.198 3.652 9.015 3.175 1.413 ms 9.963 128
Server Jitter 2604:a880:1:20::17:5001 (ntp1.glypnod.com) 0.164 0.191 0.287 0.545 2.206 3.091 4.492 1.920 2.901 0.646 0.778 ms 2.683 12.02
Server Jitter 2606:4700:f1::1 (time.cloudflare.com) 0.126 0.163 0.239 0.445 1.208 2.222 8.381 0.968 2.059 0.700 0.602 ms 8.11 82.26
Server Jitter 2606:4700:f1::123 (time.cloudflare.com) 0.280 0.291 0.338 0.651 5.888 6.127 6.186 5.550 5.835 2.489 2.412 ms 0.5428 1.35
Server Jitter SHM(0) 0.099 0.289 0.409 0.989 2.478 4.360 18.595 2.068 4.071 0.947 1.195 ms 6.422 84.12
Server Offset 2001:470:e815::24 (pi4.rellim.com) -403.108 -194.880 -61.531 6.148 72.002 102.294 115.288 133.533 297.173 50.291 2.285 µs -2.549 18.44
Server Offset 2001:470:e815::8 (spidey.rellim.com) -967.993 -945.599 -848.299 45.885 699.299 786.118 843.263 1,547.598 1,731.717 401.887 31.646 µs -0.4282 3.165
Server Offset 2001:67c:1270:0:dea6:32ff:feaf:803b (khronos.mikieboy.net) -893.194 -695.447 -335.090 -114.816 174.502 391.926 1,307.648 509.591 1,087.373 197.771 -95.487 µs 1.057 12.76
Server Offset 204.17.205.1 -1.167 -1.151 -0.970 0.040 0.436 0.468 0.499 1.405 1.619 0.365 -0.013 ms -1.561 5.386
Server Offset 204.17.205.16 -293.704 -170.578 -70.096 13.144 62.728 84.090 107.278 132.824 254.668 44.255 6.814 µs -2.097 11.74
Server Offset 204.17.205.30 -405.228 -240.007 -95.032 -16.514 38.656 62.416 79.914 133.688 302.423 52.807 -22.104 µs -3.291 21.54
Server Offset 2405:fc00::1 (robusta.dcs1.biz) 1.277 1.377 1.485 1.845 2.250 2.471 2.604 0.765 1.094 0.241 1.851 ms 0.2739 2.867
Server Offset 2604:a880:1:20::17:5001 (ntp1.glypnod.com) -1.070 -1.003 -0.945 -0.608 -0.172 -0.046 0.110 0.773 0.957 0.224 -0.592 ms 0.4661 3.056
Server Offset 2606:4700:f1::1 (time.cloudflare.com) 195.977 279.603 372.392 547.363 753.743 826.478 935.293 381.351 546.875 120.135 553.535 µs 0.09414 3.001
Server Offset 2606:4700:f1::123 (time.cloudflare.com) 382.657 389.657 417.658 525.333 886.302 938.300 951.299 468.644 548.642 175.035 602.366 µs 0.7647 2.451
Server Offset SHM(0) -150.933 -136.737 -134.870 -130.539 -126.815 -125.736 -123.752 8.055 11.001 2.500 -130.658 ms -0.5951 4.99
TDOP 0.700 0.820 0.920 1.270 2.180 3.230 6.330 1.260 2.410 0.442 1.375 2.509 14.54
Temp /dev/sda 44.000 45.000 45.000 47.000 49.000 49.000 49.000 4.000 4.000 1.512 46.872 °C
Temp /dev/sdb 34.000 34.000 34.000 36.000 38.000 38.000 38.000 4.000 4.000 1.219 36.083 °C
Temp LM0 47.000 48.000 49.000 53.000 58.000 59.000 59.000 9.000 11.000 2.887 53.236 °C
Temp LM1 44.250 44.484 44.750 47.625 74.831 76.157 77.500 30.081 31.674 10.849 52.589 °C
Temp LM10 25.000 25.000 25.000 25.000 25.000 25.130 26.000 0.000 0.130 0.102 25.010 °C
Temp LM11 61.000 61.000 62.000 63.000 64.000 64.000 64.000 2.000 3.000 0.801 62.896 °C
Temp LM12 3.000 3.000 5.000 12.000 20.000 23.000 24.000 15.000 20.000 4.645 12.608 °C
Temp LM13 25.000 25.000 25.000 25.000 25.000 26.000 26.000 0.000 1.000 0.117 25.014 °C
Temp LM14 43.000 43.000 43.000 44.000 46.000 46.000 46.000 3.000 3.000 0.954 44.295 °C
Temp LM15 35.000 36.000 36.000 38.000 63.000 65.000 66.000 27.000 29.000 10.042 42.597 °C
Temp LM16 66.500 66.935 67.000 68.000 69.000 69.000 69.000 2.000 2.065 0.592 68.083 °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 41.000 42.250 42.500 44.125 74.162 77.630 79.500 31.662 35.380 11.748 50.291 °C
Temp LM20 44.250 44.500 44.750 47.625 74.875 76.141 77.625 30.125 31.641 10.881 52.498 °C
Temp LM21 66.750 66.968 67.250 68.000 69.000 69.000 69.000 1.750 2.032 0.575 68.206 °C
Temp LM22 34.000 34.000 35.000 36.000 38.000 38.000 38.000 3.000 4.000 1.141 36.205 °C
Temp LM23 64.850 64.850 64.850 67.850 69.850 69.850 70.850 5.000 5.000 1.529 67.787 °C
Temp LM3 44.000 45.000 45.000 47.000 49.000 49.000 49.000 4.000 4.000 1.512 46.889 °C
Temp LM4 48.850 48.850 48.850 50.850 52.850 54.850 55.850 4.000 6.000 1.212 50.524 °C
Temp LM5 48.850 48.850 48.850 50.850 52.850 54.850 55.850 4.000 6.000 1.192 50.524 °C
Temp LM6 54.850 56.850 56.850 58.850 63.850 69.980 73.850 7.000 13.130 2.609 59.333 °C
Temp LM7 48.850 48.850 48.850 50.850 52.850 54.850 55.850 4.000 6.000 1.176 50.534 °C
Temp LM8 43.000 43.000 43.000 44.000 46.000 46.000 46.000 3.000 3.000 0.962 44.302 °C
Temp LM9 36.000 36.500 36.500 38.000 52.000 52.500 52.500 15.500 16.000 5.622 40.361 °C
nSats 6.000 8.000 9.000 12.000 14.000 15.000 16.000 5.000 7.000 1.401 11.532 nSat -0.001175 2.89
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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