Messages in this thread | | | From | "Justin Piszcz" <> | Subject | X9SCM-F-O clock drift +1 second into the future when ntp running? | Date | Sat, 7 Jul 2012 11:12:25 -0400 |
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Hello,
I migrated from an X7SPA to an X9SCM-F-O and now gpsd/ntp no longer sync with my GPS unit: http://www.amazon.com/GlobalSat-BU-353-USB-GPS-Receiver/dp/B000PKX2KA
I did some digging and it looks like the system clock on this motherboard with the latest BIOS (2.00a) runs 1 second too fast when comparing to other NTP-synchronized machines.
When comparing the clock on this vs. an atomic clock, the system clock is ~1 second faster, which is probably why the GPS has problems syncing.
Is this a faulty motherboard clock or is this an issue with Ivy Bridge (I am using an E3-1200 V2 CPU) with the X9SCM-F-O and BIOS 2.00a?
DMI Info:
Handle 0x0000, DMI type 0, 24 bytes BIOS Information Vendor: American Megatrends Inc. Version: 2.0a Release Date: 06/08/2012 Address: 0xF0000 Runtime Size: 64 kB ROM Size: 8192 kB
NTP problem:
Problem, the x127 for the GPS:
$ ntpq -pn remote refid st t when poll reach delay offset jitter ============================================================================ == x127.127.28.0 .GPS. 0 l 11 16 377 0.000 0.363 100.414 *204.235.61.9 128.174.38.133 2 u 48 64 37 48.716 -985.27 326.767 +184.105.192.247 216.218.254.202 2 u 43 64 37 90.902 -987.55 332.766 +50.7.247.114 85.114.26.194 2 u 42 64 37 158.445 -985.19 330.627 +69.65.40.29 209.51.161.238 2 u 43 64 37 47.733 -984.50 329.232
Any idea why it consistently has a ~1 second offset? Is there a good way to fix this?
Before, on the X7SPA I ran gpsd+ntp for years without any issues, it synchronized perfectly. Is this a BIOS issue? Kernel problem or HW issue?
$ cat /sys/devices/system/clocksource/clocksource0/current_clocksource tsc
Full output:
# adjtimex -p mode: 0 offset: 0 frequency: 1523449 maxerror: 16000000 esterror: 16000000 status: 8257 time_constant: 3 precision: 1 tolerance: 32768000 tick: 10015 raw time: 1341673069s 873569969us = 1341673069.873569969 return value = 5
After 5-10 minutes without ntpd running, the clock had drifted -2.27 seconds the other direction..
# ntpdate time.nist.gov 7 Jul 11:03:32 ntpdate[374]: step time server 128.138.140.44 offset -2.273077 sec
Justin.
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