NTPsec

Kong

Report generated: Sat Feb 22 14:59:01 2025 UTC
Start Time: Sat Feb 15 14:59:00 2025 UTC
End Time: Sat Feb 22 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 -575.142 -166.807 -51.622 -2.315 48.013 172.222 456.796 99.635 339.030 51.560 -2.073 µs -0.5267 33.33
Local Clock Frequency Offset 11.375 11.430 11.460 12.079 13.764 13.858 13.915 2.304 2.428 0.625 12.163 ppm 1.55 4.879

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 7.703 9.823 12.372 23.050 48.636 76.402 117.203 36.264 66.579 12.435 25.628 µs 2.476 12.51

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 3.527 4.730 6.040 11.791 58.595 129.976 219.819 52.555 125.246 21.804 17.812 ppb 4.221 23.55

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

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

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



Local Clock Time Offset Histogram

local offset histogram plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Local Clock Offset -575.142 -166.807 -51.622 -2.315 48.013 172.222 456.796 99.635 339.030 51.560 -2.073 µs -0.5267 33.33

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 11.375 11.430 11.460 12.079 13.764 13.858 13.915 2.304 2.428 0.625 12.163 ppm 1.55 4.879
Temp /dev/sda 44.000 44.000 44.000 47.000 49.000 50.000 50.000 5.000 6.000 1.400 46.554 °C
Temp /dev/sdb 32.000 32.000 32.000 34.000 36.000 38.000 38.000 4.000 6.000 1.269 34.366 °C
Temp LM0 48.000 49.000 50.000 56.000 58.000 58.000 59.000 8.000 9.000 2.473 54.874 °C
Temp LM1 37.750 39.125 40.250 45.500 73.250 74.484 83.875 33.000 35.359 9.401 48.003 °C
Temp LM10 25.000 25.000 25.000 25.000 25.000 26.000 26.000 0.000 1.000 0.131 25.017 °C
Temp LM11 61.000 61.000 62.000 63.000 63.000 64.000 65.000 1.000 3.000 0.636 62.594 °C
Temp LM12 3.000 4.000 4.000 5.000 18.000 23.000 35.000 14.000 19.000 4.754 7.476 °C
Temp LM13 25.000 25.000 25.000 25.000 25.000 25.000 26.000 0.000 0.000 0.089 25.008 °C
Temp LM14 42.000 43.000 43.000 44.000 45.000 45.000 46.000 2.000 2.000 0.651 44.148 °C
Temp LM15 33.000 34.000 34.000 38.000 62.000 63.000 72.000 28.000 29.000 7.903 40.154 °C
Temp LM16 66.000 66.500 67.000 68.000 68.500 69.000 69.500 1.500 2.500 0.534 67.909 °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 37.500 39.000 40.500 45.750 72.750 74.750 83.500 32.250 35.750 9.161 48.396 °C
Temp LM20 37.750 39.125 40.250 45.500 73.250 74.500 83.875 33.000 35.375 9.397 47.989 °C
Temp LM21 66.250 66.750 67.000 68.000 68.875 69.000 69.750 1.875 2.250 0.526 68.041 °C
Temp LM22 32.000 32.000 33.000 35.000 36.000 38.000 38.000 3.000 6.000 1.233 34.449 °C
Temp LM23 63.850 67.850 68.850 70.850 71.850 71.850 72.850 3.000 4.000 0.936 70.297 °C
Temp LM3 44.000 44.000 44.000 47.000 49.000 50.000 50.000 5.000 6.000 1.402 46.558 °C
Temp LM4 47.850 48.850 49.850 50.850 51.850 54.850 57.850 2.000 6.000 0.825 50.969 °C
Temp LM5 46.850 48.850 49.850 50.850 51.850 54.850 57.850 2.000 6.000 0.834 50.980 °C
Temp LM6 55.850 56.850 57.850 59.850 62.850 69.850 74.850 5.000 13.000 2.046 59.641 °C
Temp LM7 47.850 48.850 49.850 50.850 51.850 54.850 57.850 2.000 6.000 0.831 50.974 °C
Temp LM8 42.000 43.000 43.000 44.000 45.000 45.000 47.000 2.000 2.000 0.651 44.149 °C
Temp LM9 33.000 34.000 34.500 38.000 51.000 51.500 52.500 16.500 17.500 4.377 39.010 °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 4.000 7.000 9.000 10.000 11.000 5.000 6.000 1.450 6.653 nSat 0.08242 2.472
TDOP 0.810 1.010 1.180 2.190 9.730 31.544 159.940 8.550 30.534 6.366 3.755 8.7 111.4

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) -596.857 -183.812 -52.941 17.537 96.283 198.217 562.014 149.223 382.029 64.129 18.297 µs -0.2944 24.47

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) -1,339.012 -781.990 -608.922 15.393 332.986 543.525 858.404 941.908 1,325.515 270.803 -19.191 µs -0.9577 5.06

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) -2.495 -1.217 -1.077 -0.764 -0.118 0.118 0.698 0.959 1.335 0.307 -0.697 ms 0.7337 4.287

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 -2.093 -1.352 -1.064 0.045 0.566 1.108 1.361 1.630 2.460 0.463 -0.024 ms -0.9228 4.982

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 -554.354 -174.732 -89.992 -30.326 18.698 95.199 474.391 108.690 269.931 47.766 -30.925 µs -0.3107 31.58

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) -25.425 -22.677 -20.922 0.059 0.558 0.814 15.755 21.480 23.491 6.679 -2.775 ms -2.035 5.642

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) -1.288 -1.061 -0.834 -0.359 0.135 0.328 1.603 0.969 1.388 0.306 -0.355 ms 0.1608 3.526

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) -0.137 0.163 0.306 0.567 0.870 1.089 1.371 0.564 0.926 0.181 0.572 ms 0.3681 4.794

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) -0.195 0.260 0.400 0.622 0.926 1.065 1.326 0.526 0.805 0.161 0.634 ms 0.2154 4.524

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) -164.926 -130.754 -128.986 -124.921 -120.911 -119.568 -116.954 8.074 11.186 2.579 -124.912 ms -1.027 11.85

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 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) 0.001 0.003 0.005 0.015 0.076 0.128 6.978 0.072 0.124 0.228 0.033 ms 25.24 670.3

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 2001:470: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) 1.241 2.615 3.890 10.899 43.037 112.300 252.380 39.147 109.684 19.038 16.468 µs 4.632 33.68

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) 0.059 0.192 0.277 0.675 3.886 11.743 133.684 3.609 11.551 5.892 1.538 ms 15.18 289.3

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 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 1.628 2.928 4.790 15.310 58.430 119.414 297.049 53.640 116.486 23.238 21.982 µs 4.044 27.59

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 1.770 4.433 6.284 17.048 74.282 170.307 417.272 67.997 165.874 32.248 25.786 µs 5.264 41.7

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) 0.118 0.198 0.292 0.823 8.033 13.861 49.540 7.741 13.663 3.660 2.053 ms 6.486 66.65

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 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) 0.094 0.176 0.252 0.583 2.606 7.993 64.126 2.354 7.818 3.114 1.101 ms 14.13 246.4

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

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

RMS Jitter is field 8 in the peerstats log file.



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

peer jitter 2606:4700:f1::1 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2606:4700:f1::1 (time.cloudflare.com) 0.087 0.170 0.233 0.480 3.343 7.845 55.744 3.110 7.675 4.463 1.198 ms 10.49 121.8

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) 0.115 0.172 0.244 0.483 1.494 3.278 7.697 1.250 3.106 0.602 0.622 ms 6.168 58.85

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) 0.000 0.256 0.369 0.889 2.328 6.489 35.218 1.959 6.234 1.208 1.126 ms 9.348 148.6

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 11.375 11.430 11.460 12.079 13.764 13.858 13.915 2.304 2.428 0.625 12.163 ppm 1.55 4.879
Local Clock Time Offset -575.142 -166.807 -51.622 -2.315 48.013 172.222 456.796 99.635 339.030 51.560 -2.073 µs -0.5267 33.33
Local RMS Frequency Jitter 3.527 4.730 6.040 11.791 58.595 129.976 219.819 52.555 125.246 21.804 17.812 ppb 4.221 23.55
Local RMS Time Jitter 7.703 9.823 12.372 23.050 48.636 76.402 117.203 36.264 66.579 12.435 25.628 µs 2.476 12.51
Server Jitter 2001:470:e815::24 (pi4.rellim.com) 0.001 0.003 0.005 0.015 0.076 0.128 6.978 0.072 0.124 0.228 0.033 ms 25.24 670.3
Server Jitter 2001:470:e815::8 (spidey.rellim.com) 1.241 2.615 3.890 10.899 43.037 112.300 252.380 39.147 109.684 19.038 16.468 µs 4.632 33.68
Server Jitter 2001:67c:1270:0:dea6:32ff:feaf:803b (khronos.mikieboy.net) 0.059 0.192 0.277 0.675 3.886 11.743 133.684 3.609 11.551 5.892 1.538 ms 15.18 289.3
Server Jitter 204.17.205.1 1.628 2.928 4.790 15.310 58.430 119.414 297.049 53.640 116.486 23.238 21.982 µs 4.044 27.59
Server Jitter 204.17.205.30 1.770 4.433 6.284 17.048 74.282 170.307 417.272 67.997 165.874 32.248 25.786 µs 5.264 41.7
Server Jitter 2405:fc00::1 (robusta.dcs1.biz) 0.118 0.198 0.292 0.823 8.033 13.861 49.540 7.741 13.663 3.660 2.053 ms 6.486 66.65
Server Jitter 2604:a880:1:20::17:5001 (ntp1.glypnod.com) 0.094 0.176 0.252 0.583 2.606 7.993 64.126 2.354 7.818 3.114 1.101 ms 14.13 246.4
Server Jitter 2606:4700:f1::1 (time.cloudflare.com) 0.087 0.170 0.233 0.480 3.343 7.845 55.744 3.110 7.675 4.463 1.198 ms 10.49 121.8
Server Jitter 2606:4700:f1::123 (time.cloudflare.com) 0.115 0.172 0.244 0.483 1.494 3.278 7.697 1.250 3.106 0.602 0.622 ms 6.168 58.85
Server Jitter SHM(0) 0.000 0.256 0.369 0.889 2.328 6.489 35.218 1.959 6.234 1.208 1.126 ms 9.348 148.6
Server Offset 2001:470:e815::24 (pi4.rellim.com) -596.857 -183.812 -52.941 17.537 96.283 198.217 562.014 149.223 382.029 64.129 18.297 µs -0.2944 24.47
Server Offset 2001:470:e815::8 (spidey.rellim.com) -1,339.012 -781.990 -608.922 15.393 332.986 543.525 858.404 941.908 1,325.515 270.803 -19.191 µs -0.9577 5.06
Server Offset 2001:67c:1270:0:dea6:32ff:feaf:803b (khronos.mikieboy.net) -2.495 -1.217 -1.077 -0.764 -0.118 0.118 0.698 0.959 1.335 0.307 -0.697 ms 0.7337 4.287
Server Offset 204.17.205.1 -2.093 -1.352 -1.064 0.045 0.566 1.108 1.361 1.630 2.460 0.463 -0.024 ms -0.9228 4.982
Server Offset 204.17.205.30 -554.354 -174.732 -89.992 -30.326 18.698 95.199 474.391 108.690 269.931 47.766 -30.925 µs -0.3107 31.58
Server Offset 2405:fc00::1 (robusta.dcs1.biz) -25.425 -22.677 -20.922 0.059 0.558 0.814 15.755 21.480 23.491 6.679 -2.775 ms -2.035 5.642
Server Offset 2604:a880:1:20::17:5001 (ntp1.glypnod.com) -1.288 -1.061 -0.834 -0.359 0.135 0.328 1.603 0.969 1.388 0.306 -0.355 ms 0.1608 3.526
Server Offset 2606:4700:f1::1 (time.cloudflare.com) -0.137 0.163 0.306 0.567 0.870 1.089 1.371 0.564 0.926 0.181 0.572 ms 0.3681 4.794
Server Offset 2606:4700:f1::123 (time.cloudflare.com) -0.195 0.260 0.400 0.622 0.926 1.065 1.326 0.526 0.805 0.161 0.634 ms 0.2154 4.524
Server Offset SHM(0) -164.926 -130.754 -128.986 -124.921 -120.911 -119.568 -116.954 8.074 11.186 2.579 -124.912 ms -1.027 11.85
TDOP 0.810 1.010 1.180 2.190 9.730 31.544 159.940 8.550 30.534 6.366 3.755 8.7 111.4
Temp /dev/sda 44.000 44.000 44.000 47.000 49.000 50.000 50.000 5.000 6.000 1.400 46.554 °C
Temp /dev/sdb 32.000 32.000 32.000 34.000 36.000 38.000 38.000 4.000 6.000 1.269 34.366 °C
Temp LM0 48.000 49.000 50.000 56.000 58.000 58.000 59.000 8.000 9.000 2.473 54.874 °C
Temp LM1 37.750 39.125 40.250 45.500 73.250 74.484 83.875 33.000 35.359 9.401 48.003 °C
Temp LM10 25.000 25.000 25.000 25.000 25.000 26.000 26.000 0.000 1.000 0.131 25.017 °C
Temp LM11 61.000 61.000 62.000 63.000 63.000 64.000 65.000 1.000 3.000 0.636 62.594 °C
Temp LM12 3.000 4.000 4.000 5.000 18.000 23.000 35.000 14.000 19.000 4.754 7.476 °C
Temp LM13 25.000 25.000 25.000 25.000 25.000 25.000 26.000 0.000 0.000 0.089 25.008 °C
Temp LM14 42.000 43.000 43.000 44.000 45.000 45.000 46.000 2.000 2.000 0.651 44.148 °C
Temp LM15 33.000 34.000 34.000 38.000 62.000 63.000 72.000 28.000 29.000 7.903 40.154 °C
Temp LM16 66.000 66.500 67.000 68.000 68.500 69.000 69.500 1.500 2.500 0.534 67.909 °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 37.500 39.000 40.500 45.750 72.750 74.750 83.500 32.250 35.750 9.161 48.396 °C
Temp LM20 37.750 39.125 40.250 45.500 73.250 74.500 83.875 33.000 35.375 9.397 47.989 °C
Temp LM21 66.250 66.750 67.000 68.000 68.875 69.000 69.750 1.875 2.250 0.526 68.041 °C
Temp LM22 32.000 32.000 33.000 35.000 36.000 38.000 38.000 3.000 6.000 1.233 34.449 °C
Temp LM23 63.850 67.850 68.850 70.850 71.850 71.850 72.850 3.000 4.000 0.936 70.297 °C
Temp LM3 44.000 44.000 44.000 47.000 49.000 50.000 50.000 5.000 6.000 1.402 46.558 °C
Temp LM4 47.850 48.850 49.850 50.850 51.850 54.850 57.850 2.000 6.000 0.825 50.969 °C
Temp LM5 46.850 48.850 49.850 50.850 51.850 54.850 57.850 2.000 6.000 0.834 50.980 °C
Temp LM6 55.850 56.850 57.850 59.850 62.850 69.850 74.850 5.000 13.000 2.046 59.641 °C
Temp LM7 47.850 48.850 49.850 50.850 51.850 54.850 57.850 2.000 6.000 0.831 50.974 °C
Temp LM8 42.000 43.000 43.000 44.000 45.000 45.000 47.000 2.000 2.000 0.651 44.149 °C
Temp LM9 33.000 34.000 34.500 38.000 51.000 51.500 52.500 16.500 17.500 4.377 39.010 °C
nSats 4.000 4.000 4.000 7.000 9.000 10.000 11.000 5.000 6.000 1.450 6.653 nSat 0.08242 2.472
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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