bioc clock drifts several minutes every day

[merk]

Would a bad bios battery apply even if the machine is left on 24/7? The clock on my PVR machine routinely drifts several minutes each day. Right now i set windows to do a time update every 12 hours. Although i think i may have to make it update even more often then that since the click can drift 2-4 minutes even in just 12 hours. I'd be much happier if the clock just wasnt so flakey.

Its a bit of a pain to get at the bios battery which is why i havent replaced it yet. I wasnt sure the bios battery would matter since the machine is always powered on. What else could cause the clock to become so in-accurate?

 

[dman]

That's a pretty big gap, but I agree, battery not likely to fix it as with the machine powered up it should not have any impact.

It is possible that it's not the bios clock that's losing time and it's the windows clock? If the cpu is being pegged a lot, it may be losing time that way. I guess, does it happen even when the system is idle? Perhaps it's a standby problem... in which case the batter may be suspect--but usually the bios doesn't need battery as long as the system is plugged in and has power at the outlet.

 

[merk]

well, the machine does duty as a PVR so the cpu does spike occasionally right after it finishes a recording as it scans through the video file tagging the commercials. and i occasionally recompress the video which also hogs up the cpu.

But, wouldnt the clock slow down if its due to the cpu being heavily used? I find that the clock is always running fast.

I suppose i could test it easily enough. after making sure the clock is correct I could just shut down the machine for a few hours and then see if the time has drifted again.

any particular time syncing software you'd suggest? right now i just tweaked the windows registry so that the windows time update is kicking in every 6 hours (had it set to 12 but thats not often enough).

thanks

 

[cjard]

the clock is driven by a separate oscillator crystal and is not linked to the cpu for timing purposes. the first thing to try would be to replace the battery. then, you can ensure that the system is not overclocked (even though it wouldnt make a difference froma speed point of view, the extra emi might) and turn on "Spread Spectrum Modulated" in bios.. this will reduce the EMI within the case..

if it doesnt work, then you can either set windows to sync the time with time.windows.com every 30 minutes, or buy another motherboard

 

[cjard]

incidentally, does it go out of sync when you leave it on the bios screen, or only in windows..? enter the bios basic cmos setup screen and set the time overnight, then return and check the next day.. is the clock on the bios screen wrong?