System clock inaccuracy issue

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irads

System clock inaccuracy issue

Post by irads »

There is a known issue with system clock inaccuracy in fit-PC2 and fit-PC2i.
CompuLab R&D has been able to reproduce the problem and is now investigating it.

Findings so far
The investigation reveals that RTC is perfectly correct while the system timer constantly misses ticks.

Tests indicate that it happens in two scenarios:
1. When C-States are enabled in BIOS.
Disabling C-States in BIOS - Intel / CPU Control Sub-Menu to "GV3 only" resolves the problem in this case.
2. When DPMS (monitor off when unused) is enabled and used many times.
In that case - changing power management settings in BIOS does not affect the problem.

Further research is taking place. CompuLab will issue an update when there are more findings.

Workaround options
Update system clock frequently from RTC. CompuLab will be offering a utility for that.

Enable NTPD to frequently update system clock from a time server.

Note: for clarity, this thread is locked for discussions. Please discuss specific related issues in another thread.

irads

Re: System clock inaccuracy issue

Post by irads »

CompuLab investigation did not reveal system clock inaccuracy under Windows XP. However, if a user is experiencing such a problem, this utility should solve that - http://www.softdevlabs.com/ClockMon/ClockMon.html

It periodically synchronizes system clock to HW RTC.

irads

Synchronizing system clock in Linux

Post by irads »

To synchronize system clock to HW RTC:

Adjust system clock through NTP

Code: Select all

sudo ntpdate -u pool.ntp.org
Synchronize HW RTC to system clock

Code: Select all

sudo hwclock -w
Edit system crontab file

Code: Select all

sudo crontab -e
Add this line to update system clock from HW RTC every 5 minutes

Code: Select all

*/5 * * * * /sbin/hwclock -s

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