On Sat, Nov 6, 2010 at 03:34 UTC, David L. Mills <mi...@udel.edu> wrote: > Now to the apparent initial frequency error. This is new, as tests in the > past have not confirmed that. I need to plant some debug code in > direct-freq().
I ran several more tests without a drift file on the same FreeBSD 6.4 machine, but now with the daemon loop. The kernel frequency was reset with ntptime -f 0. This is using ntpd 4.2.7p78 with four LAN sources each with less than 500ms delay on gigabit ethernet, maxpoll 6 and iburst on each. The machine's drift when settled stays over 79 and under 81 PPM. 55506 60099.298 0.112224703 0.000 0.039677424 0.000000 6 55506 60430.299 0.087985591 265.808 0.031875465 0.000000 6 55506 60497.299 0.082268047 265.808 0.029885212 0.000000 6 55506 60501.299 0.063703305 265.808 0.028715263 0.000000 6 55506 60566.299 0.044976216 265.808 0.027664662 0.000000 6 55506 60570.299 0.035161159 265.808 0.026109553 0.000000 6 55506 60632.299 0.016835865 265.808 0.025268008 0.000000 6 55506 60637.300 0.007505765 265.808 0.023865132 0.000000 6 55506 60699.299 -0.005871398 265.808 0.022819291 0.000000 6 55506 60703.299 -0.012182324 265.808 0.021461792 0.000000 6 Above I slowed the clock by 110ms before starting ntpd, and its frequency estimate is 3x too big. 55506 61035.172 -0.109110664 0.000 0.038576445 0.000000 6 55506 61364.172 -0.039509331 -120.080 0.047442141 0.000000 6 55506 61432.172 -0.018407984 -120.080 0.045000783 0.000000 6 55506 61441.171 -0.000743150 -120.080 0.042555170 0.000000 6 55506 61570.172 -0.039411530 -120.383 0.042088955 0.107139 6 55506 61907.172 0.077963129 -118.817 0.057202679 0.562671 6 55506 62109.172 0.112914955 -117.457 0.054916590 0.712782 6 55506 62588.325 0.000000000 -117.457 0.000001907 0.666746 6 55506 62597.324 0.036879681 -117.437 0.013038936 0.623723 6 This time opposite offset and the drift ends up with the wrong sign. 55506 62673.088 0.046002361 0.000 0.016264291 0.000000 6 55506 63004.087 0.036022038 108.824 0.016594865 0.000000 6 55506 63072.088 0.024200794 108.824 0.016075870 0.000000 6 55506 63076.087 0.015639317 108.824 0.015339223 0.000000 6 55506 63139.087 0.007153841 108.824 0.014658809 0.000000 6 55506 63144.087 -0.001147804 108.824 0.014022670 0.000000 6 55506 63342.087 0.010581006 108.949 0.013756870 0.044150 6 55506 63546.087 -0.007289204 108.860 0.014335728 0.051841 6 55506 64089.087 -0.018442062 108.263 0.013977562 0.216530 6 55506 64156.087 -0.025361028 108.162 0.013301681 0.205686 6 55506 64224.087 -0.025423666 108.059 0.012442603 0.195821 6 46ms slow, frequency is ~28 PPM too large. 55506 64548.716 0.001700028 0.000 0.000601053 0.000000 6 55506 64879.717 0.023679569 71.539 0.010183162 0.000000 6 55506 64946.717 0.019872424 71.539 0.009620108 0.000000 6 55506 65013.717 0.002736900 71.539 0.010848108 0.000000 6 55506 65017.717 -0.008305963 71.539 0.010872643 0.000000 6 55506 65082.716 -0.004770959 71.539 0.010246931 0.000000 6 55506 65148.717 0.001608567 71.539 0.009846926 0.000000 6 55506 65219.717 0.012919477 71.594 0.010041603 0.019330 6 55506 65346.717 0.011396322 71.680 0.009408484 0.035457 6 55506 65486.716 0.003467074 71.709 0.009236544 0.034709 6 55506 65828.717 0.004913697 71.809 0.008655121 0.048044 6 55506 66236.717 0.006136544 71.959 0.008107660 0.069307 6 55506 66627.716 0.007779940 72.140 0.007606245 0.091173 6 55506 66776.716 0.009039619 72.220 0.007128916 0.089883 6 55506 67230.717 0.009392249 72.474 0.006669656 0.123060 6 55506 67373.716 0.009373844 72.554 0.006238895 0.118527 6 55506 67658.716 0.009579650 72.717 0.005836406 0.124912 6 55506 67908.717 0.009567647 72.860 0.005459459 0.127253 6 55506 67977.716 0.009286340 72.898 0.005107825 0.119797 6 55506 68513.717 0.009503342 73.201 0.004778549 0.155178 6 55506 68642.716 0.009570171 73.275 0.004469985 0.147469 6 55506 69168.716 0.009184942 73.563 0.004183506 0.171447 6 55506 69233.716 0.009189485 73.599 0.003913312 0.160868 6 55506 69365.716 0.009375908 73.672 0.003661161 0.152721 6 55506 69432.717 0.009193983 73.709 0.003425307 0.143446 6 55506 69959.717 0.008999743 73.992 0.003204817 0.167315 6 55506 70090.717 0.009024846 74.062 0.002997845 0.158480 6 55506 70155.716 0.008902531 74.097 0.002804561 0.148745 6 55506 70350.716 0.008570129 74.196 0.002626057 0.143526 6 55506 70672.716 0.008251968 74.355 0.002459026 0.145465 6 55506 71197.716 0.007350799 74.585 0.002322169 0.158521 6 55506 71456.716 0.007408970 74.699 0.002172288 0.153698 6 55506 71850.716 0.007506679 74.875 0.002032283 0.156700 6 55506 72376.716 0.007566595 75.113 0.001901145 0.168879 6 55506 72899.717 0.007325361 75.341 0.001780402 0.177408 6 55506 72965.716 0.007008212 75.368 0.001669184 0.166236 6 55506 73491.716 0.006596605 75.575 0.001568146 0.171833 6 55506 73689.716 0.006589897 75.653 0.001466868 0.163070 6 55506 74212.717 0.006427589 75.853 0.001373329 0.168186 6 55506 74407.717 0.006501221 75.929 0.001284895 0.159575 6 55506 74537.723 0.006513531 75.979 0.001201917 0.150332 6 55506 74672.717 0.006297412 76.030 0.001126884 0.141759 6 55506 74999.716 0.006044827 76.148 0.001057880 0.138992 6 55506 75524.716 0.005710565 76.327 0.000996588 0.144553 6 55506 75981.716 0.005532070 76.477 0.000934356 0.145334 6 55506 76313.716 0.005505819 76.586 0.000874059 0.141300 6 55506 76442.716 0.005524893 76.629 0.000817635 0.133025 6 55506 76768.716 0.005369956 76.733 0.000766787 0.129787 6 55506 77228.716 0.004834798 76.866 0.000741799 0.130137 6 55506 77685.716 0.004784225 76.996 0.000694120 0.130159 6 55506 78207.716 0.004621958 77.140 0.000651820 0.131942 6 55506 78273.716 0.004610433 77.158 0.000609735 0.123587 6 55506 78667.717 0.004535789 77.264 0.000570965 0.121585 6 55506 79191.716 0.004254460 77.397 0.000543272 0.123053 6 55506 79387.724 0.004210196 77.447 0.000508425 0.116412 6 55506 79451.716 0.004094866 77.462 0.000477333 0.109034 6 55506 79648.717 0.004053887 77.510 0.000446739 0.103371 6 55506 80173.716 0.003811266 77.629 0.000426599 0.105488 6 55506 80239.717 0.003807079 77.644 0.000399050 0.098817 6 55506 80761.716 0.003781913 77.762 0.000373383 0.101366 6 55506 80826.716 0.003742947 77.776 0.000349539 0.094957 6 55506 81286.717 0.003719909 77.878 0.000327066 0.095865 6 55506 81810.723 0.003575463 77.990 0.000310175 0.097981 6 55506 82008.717 0.003563863 78.032 0.000290171 0.092851 6 55506 82075.716 0.003460594 78.046 0.000273875 0.086991 6 55506 82139.716 0.003368641 78.059 0.000258241 0.081500 6 55506 82664.716 0.003331264 78.163 0.000241923 0.084677 6 55506 83058.716 0.003307356 78.240 0.000226456 0.083834 6 55506 83321.717 0.003079668 78.289 0.000226611 0.080255 6 55506 83452.716 0.002969860 78.312 0.000215501 0.075518 6 55506 83517.717 0.002958930 78.323 0.000201620 0.070757 6 55506 83646.716 0.002923137 78.346 0.000189022 0.066662 6 55506 84169.717 0.002828842 78.434 0.000179929 0.069717 6 55506 84233.716 0.002829801 78.445 0.000168310 0.065326 6 55506 84299.716 0.002810263 78.456 0.000157591 0.061232 6 55506 84823.716 0.002667552 78.539 0.000155809 0.064407 6 55506 85146.716 0.002627148 78.590 0.000146444 0.062845 6 55506 85601.716 0.002466953 78.657 0.000148233 0.063367 6 55506 86006.716 0.002419676 78.715 0.000139663 0.062769 6 55506 86122.717 0.002411172 78.732 0.000130677 0.059010 6 55506 86188.716 0.002383291 78.741 0.000122634 0.055298 6 Under 2ms initial offset, the frequency estimate is ~8 PPM too small. Cheers, Dave Hart _______________________________________________ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
