NTPsec

Kong

Report generated: Fri Jan 17 14:59:01 2025 UTC
Start Time: Fri Jan 10 14:59:00 2025 UTC
End Time: Fri Jan 17 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 -120.147 -46.702 -2.256 45.530 120.127 601.468 92.232 240.274 45.853 -1.859 µs 0.5036 41.2
Local Clock Frequency Offset 11.460 11.530 11.610 11.973 13.765 13.941 14.001 2.155 2.412 0.499 12.067 ppm 2.718 10.39

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 10.463 12.565 21.686 43.621 73.673 134.781 31.056 63.210 11.554 23.882 µs 3.29 20.4

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 5.020 6.276 12.288 46.072 123.675 238.733 39.797 118.656 20.245 17.395 ppb 4.938 33.2

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 -120.147 -46.702 -2.256 45.530 120.127 601.468 92.232 240.274 45.853 -1.859 µs 0.5036 41.2

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 11.460 11.530 11.610 11.973 13.765 13.941 14.001 2.155 2.412 0.499 12.067 ppm 2.718 10.39
Temp /dev/sda 44.000 44.000 44.000 47.000 49.000 50.000 51.000 5.000 6.000 1.522 46.795 °C
Temp /dev/sdb 33.000 34.000 34.000 36.000 38.000 39.000 40.000 4.000 5.000 1.330 35.963 °C
Temp LM0 48.000 49.000 49.000 54.000 58.000 59.000 60.000 9.000 10.000 2.777 53.659 °C
Temp LM1 41.375 42.125 43.250 46.125 74.250 75.875 79.250 31.000 33.750 7.409 48.020 °C
Temp LM10 25.000 25.000 25.000 25.000 25.000 25.000 26.000 0.000 0.000 0.063 25.004 °C
Temp LM11 61.000 61.000 61.000 62.000 64.000 64.000 65.000 3.000 3.000 0.775 62.486 °C
Temp LM12 2.000 3.000 5.000 13.000 21.000 23.000 28.000 16.000 20.000 4.619 13.186 °C
Temp LM13 25.000 25.000 25.000 25.000 25.000 25.000 26.000 0.000 0.000 0.067 25.004 °C
Temp LM14 42.000 42.000 43.000 44.000 46.000 46.000 46.000 3.000 4.000 0.929 43.861 °C
Temp LM15 34.000 35.000 36.000 37.000 63.000 64.000 68.000 27.000 29.000 6.598 38.952 °C
Temp LM16 66.000 66.500 67.000 67.500 69.000 69.000 69.500 2.000 2.500 0.604 67.731 °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 40.000 41.000 41.750 43.750 72.500 75.000 81.500 30.750 34.000 7.844 46.511 °C
Temp LM20 41.375 42.125 43.250 46.125 74.250 75.875 79.500 31.000 33.750 7.408 47.983 °C
Temp LM21 66.250 66.750 67.000 67.875 69.000 69.375 69.500 2.000 2.625 0.585 67.865 °C
Temp LM22 33.000 34.000 34.000 36.000 38.000 39.000 40.000 4.000 5.000 1.292 36.000 °C
Temp LM23 63.850 64.850 64.850 67.850 69.850 70.850 70.850 5.000 6.000 1.523 67.984 °C
Temp LM3 44.000 44.000 44.000 47.000 49.000 50.000 51.000 5.000 6.000 1.521 46.812 °C
Temp LM4 47.850 47.850 48.850 49.850 51.850 53.850 55.850 3.000 6.000 1.071 50.195 °C
Temp LM5 47.850 47.850 48.850 50.850 51.850 53.850 55.850 3.000 6.000 1.076 50.208 °C
Temp LM6 54.850 55.850 56.850 57.850 61.850 67.850 73.850 5.000 12.000 1.929 58.586 °C
Temp LM7 47.850 47.850 48.850 50.850 51.850 53.850 55.850 3.000 6.000 1.063 50.214 °C
Temp LM8 42.000 42.000 43.000 44.000 46.000 46.000 46.000 3.000 4.000 0.932 43.862 °C
Temp LM9 35.000 35.500 36.000 37.500 51.500 52.500 53.000 15.500 17.000 3.636 38.293 °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 5.000 8.000 9.000 11.000 14.000 15.000 17.000 5.000 7.000 1.553 11.213 nSat -0.02482 3.097
TDOP 0.700 0.840 0.930 1.350 2.320 3.240 14.000 1.390 2.400 0.503 1.459 3.013 24.03

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) -469.060 -135.557 -61.275 9.263 83.104 160.681 624.705 144.379 296.238 57.805 10.342 µs 0.6832 26.3

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 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 -896.445 -668.401 0.137 378.976 652.366 843.263 1,047.377 1,548.812 304.320 -31.924 µs -0.7159 4.021

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 -0.795 -0.409 -0.080 0.359 2.014 2.505 0.768 2.809 0.575 -0.043 ms -11.91 362.5

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 204.17.205.1

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 -1.040 0.005 0.494 0.664 1.086 1.534 2.099 0.425 -0.045 ms -1.294 5.214

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 -141.602 -50.925 11.577 71.536 161.109 735.280 122.461 302.710 54.730 11.001 µs 0.144 38.08

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 -167.627 -95.864 -18.132 49.249 110.988 542.357 145.113 278.615 57.023 -19.278 µs 0.9067 25.85

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 0.183 1.640 4.238 5.006 5.199 5.658 3.365 5.016 1.252 3.627 ms -0.6688 2.22

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 -1.159 -0.979 -0.549 0.232 1.623 2.034 1.211 2.782 0.472 -0.461 ms 2.445 11.52

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) -1,149.626 -922.136 -665.647 592.815 854.496 980.839 1,247.552 1,520.143 1,902.975 424.248 482.655 µs -2.118 6.718

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 -0.634 -0.467 0.675 2.612 2.851 3.073 3.079 3.485 0.657 0.694 ms 1.223 6.887

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 -144.104 -138.893 -130.570 -126.391 -124.929 -120.781 12.502 19.175 3.764 -131.106 ms -1.846 14.42

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 3.981 5.870 18.912 70.787 98.923 333.474 64.917 94.943 23.845 26.576 µs 3.2 24.65

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) 1.674 3.012 4.276 15.670 55.011 94.169 302.891 50.735 91.157 19.749 21.149 µs 3.592 28.52

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 0.231 0.333 1.105 28.416 37.551 108.559 28.083 37.320 10.215 6.589 ms 1.987 9.017

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 3.448 5.497 18.992 60.205 101.086 259.197 54.708 97.638 20.278 24.392 µs 3.077 21.01

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 5.906 16.135 62.282 126.809 580.006 56.375 122.689 27.387 23.238 µs 7.557 106.1

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 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 4.511 6.641 22.419 76.413 310.407 1,973.936 69.772 305.896 91.318 36.570 µs 12.47 193.7

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.



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) 0.130 0.202 0.293 0.777 4.100 7.650 45.198 3.807 7.448 1.804 1.345 ms 9.816 196.4

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 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 0.184 0.269 0.594 2.297 4.512 25.518 2.029 4.327 1.300 0.910 ms 9.98 144.1

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) 0.131 0.171 0.245 0.487 1.341 2.775 9.600 1.096 2.603 0.688 0.625 ms 8.548 97.09

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 0.169 0.243 0.505 1.659 4.433 137.636 1.416 4.264 7.637 1.157 ms 16.8 296.7

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.



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 0.292 0.420 1.096 7.737 10.931 71.000 7.317 10.639 2.458 1.996 ms 3.635 35.86

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 11.460 11.530 11.610 11.973 13.765 13.941 14.001 2.155 2.412 0.499 12.067 ppm 2.718 10.39
Local Clock Time Offset -428.997 -120.147 -46.702 -2.256 45.530 120.127 601.468 92.232 240.274 45.853 -1.859 µs 0.5036 41.2
Local RMS Frequency Jitter 3.657 5.020 6.276 12.288 46.072 123.675 238.733 39.797 118.656 20.245 17.395 ppb 4.938 33.2
Local RMS Time Jitter 7.787 10.463 12.565 21.686 43.621 73.673 134.781 31.056 63.210 11.554 23.882 µs 3.29 20.4
Server Jitter 2001:470:e815::24 (pi4.rellim.com) 1.759 3.981 5.870 18.912 70.787 98.923 333.474 64.917 94.943 23.845 26.576 µs 3.2 24.65
Server Jitter 2001:470:e815::8 (spidey.rellim.com) 1.674 3.012 4.276 15.670 55.011 94.169 302.891 50.735 91.157 19.749 21.149 µs 3.592 28.52
Server Jitter 2001:67c:1270:0:dea6:32ff:feaf:803b (khronos.mikieboy.net) 0.103 0.231 0.333 1.105 28.416 37.551 108.559 28.083 37.320 10.215 6.589 ms 1.987 9.017
Server Jitter 204.17.205.1 1.363 3.448 5.497 18.992 60.205 101.086 259.197 54.708 97.638 20.278 24.392 µs 3.077 21.01
Server Jitter 204.17.205.16 1.967 4.120 5.906 16.135 62.282 126.809 580.006 56.375 122.689 27.387 23.238 µs 7.557 106.1
Server Jitter 204.17.205.30 2.683 4.511 6.641 22.419 76.413 310.407 1,973.936 69.772 305.896 91.318 36.570 µs 12.47 193.7
Server Jitter 2405:fc00::1 (robusta.dcs1.biz) 0.130 0.202 0.293 0.777 4.100 7.650 45.198 3.807 7.448 1.804 1.345 ms 9.816 196.4
Server Jitter 2604:a880:1:20::17:5001 (ntp1.glypnod.com) 0.117 0.184 0.269 0.594 2.297 4.512 25.518 2.029 4.327 1.300 0.910 ms 9.98 144.1
Server Jitter 2606:4700:f1::1 (time.cloudflare.com) 0.131 0.171 0.245 0.487 1.341 2.775 9.600 1.096 2.603 0.688 0.625 ms 8.548 97.09
Server Jitter 2606:4700:f1::123 (time.cloudflare.com) 0.111 0.169 0.243 0.505 1.659 4.433 137.636 1.416 4.264 7.637 1.157 ms 16.8 296.7
Server Jitter SHM(0) 0.099 0.292 0.420 1.096 7.737 10.931 71.000 7.317 10.639 2.458 1.996 ms 3.635 35.86
Server Offset 2001:470:e815::24 (pi4.rellim.com) -469.060 -135.557 -61.275 9.263 83.104 160.681 624.705 144.379 296.238 57.805 10.342 µs 0.6832 26.3
Server Offset 2001:470:e815::8 (spidey.rellim.com) -1,093.232 -896.445 -668.401 0.137 378.976 652.366 843.263 1,047.377 1,548.812 304.320 -31.924 µs -0.7159 4.021
Server Offset 2001:67c:1270:0:dea6:32ff:feaf:803b (khronos.mikieboy.net) -16.541 -0.795 -0.409 -0.080 0.359 2.014 2.505 0.768 2.809 0.575 -0.043 ms -11.91 362.5
Server Offset 204.17.205.1 -1.682 -1.435 -1.040 0.005 0.494 0.664 1.086 1.534 2.099 0.425 -0.045 ms -1.294 5.214
Server Offset 204.17.205.16 -584.029 -141.602 -50.925 11.577 71.536 161.109 735.280 122.461 302.710 54.730 11.001 µs 0.144 38.08
Server Offset 204.17.205.30 -479.202 -167.627 -95.864 -18.132 49.249 110.988 542.357 145.113 278.615 57.023 -19.278 µs 0.9067 25.85
Server Offset 2405:fc00::1 (robusta.dcs1.biz) -0.466 0.183 1.640 4.238 5.006 5.199 5.658 3.365 5.016 1.252 3.627 ms -0.6688 2.22
Server Offset 2604:a880:1:20::17:5001 (ntp1.glypnod.com) -1.441 -1.159 -0.979 -0.549 0.232 1.623 2.034 1.211 2.782 0.472 -0.461 ms 2.445 11.52
Server Offset 2606:4700:f1::1 (time.cloudflare.com) -1,149.626 -922.136 -665.647 592.815 854.496 980.839 1,247.552 1,520.143 1,902.975 424.248 482.655 µs -2.118 6.718
Server Offset 2606:4700:f1::123 (time.cloudflare.com) -0.759 -0.634 -0.467 0.675 2.612 2.851 3.073 3.079 3.485 0.657 0.694 ms 1.223 6.887
Server Offset SHM(0) -215.011 -144.104 -138.893 -130.570 -126.391 -124.929 -120.781 12.502 19.175 3.764 -131.106 ms -1.846 14.42
TDOP 0.700 0.840 0.930 1.350 2.320 3.240 14.000 1.390 2.400 0.503 1.459 3.013 24.03
Temp /dev/sda 44.000 44.000 44.000 47.000 49.000 50.000 51.000 5.000 6.000 1.522 46.795 °C
Temp /dev/sdb 33.000 34.000 34.000 36.000 38.000 39.000 40.000 4.000 5.000 1.330 35.963 °C
Temp LM0 48.000 49.000 49.000 54.000 58.000 59.000 60.000 9.000 10.000 2.777 53.659 °C
Temp LM1 41.375 42.125 43.250 46.125 74.250 75.875 79.250 31.000 33.750 7.409 48.020 °C
Temp LM10 25.000 25.000 25.000 25.000 25.000 25.000 26.000 0.000 0.000 0.063 25.004 °C
Temp LM11 61.000 61.000 61.000 62.000 64.000 64.000 65.000 3.000 3.000 0.775 62.486 °C
Temp LM12 2.000 3.000 5.000 13.000 21.000 23.000 28.000 16.000 20.000 4.619 13.186 °C
Temp LM13 25.000 25.000 25.000 25.000 25.000 25.000 26.000 0.000 0.000 0.067 25.004 °C
Temp LM14 42.000 42.000 43.000 44.000 46.000 46.000 46.000 3.000 4.000 0.929 43.861 °C
Temp LM15 34.000 35.000 36.000 37.000 63.000 64.000 68.000 27.000 29.000 6.598 38.952 °C
Temp LM16 66.000 66.500 67.000 67.500 69.000 69.000 69.500 2.000 2.500 0.604 67.731 °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 40.000 41.000 41.750 43.750 72.500 75.000 81.500 30.750 34.000 7.844 46.511 °C
Temp LM20 41.375 42.125 43.250 46.125 74.250 75.875 79.500 31.000 33.750 7.408 47.983 °C
Temp LM21 66.250 66.750 67.000 67.875 69.000 69.375 69.500 2.000 2.625 0.585 67.865 °C
Temp LM22 33.000 34.000 34.000 36.000 38.000 39.000 40.000 4.000 5.000 1.292 36.000 °C
Temp LM23 63.850 64.850 64.850 67.850 69.850 70.850 70.850 5.000 6.000 1.523 67.984 °C
Temp LM3 44.000 44.000 44.000 47.000 49.000 50.000 51.000 5.000 6.000 1.521 46.812 °C
Temp LM4 47.850 47.850 48.850 49.850 51.850 53.850 55.850 3.000 6.000 1.071 50.195 °C
Temp LM5 47.850 47.850 48.850 50.850 51.850 53.850 55.850 3.000 6.000 1.076 50.208 °C
Temp LM6 54.850 55.850 56.850 57.850 61.850 67.850 73.850 5.000 12.000 1.929 58.586 °C
Temp LM7 47.850 47.850 48.850 50.850 51.850 53.850 55.850 3.000 6.000 1.063 50.214 °C
Temp LM8 42.000 42.000 43.000 44.000 46.000 46.000 46.000 3.000 4.000 0.932 43.862 °C
Temp LM9 35.000 35.500 36.000 37.500 51.500 52.500 53.000 15.500 17.000 3.636 38.293 °C
nSats 5.000 8.000 9.000 11.000 14.000 15.000 17.000 5.000 7.000 1.553 11.213 nSat -0.02482 3.097
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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