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Recently I discovered that my system clock was slowing down. I got a new CMOS battery and replaced the one already on the motherboard. Both of the batteries seemed to have good voltage with a tongue test. However, two days after I re-synchronized the clock over the internet, I have lost 9 minutes and 15 seconds.

Does anyone know what could be causing the problem? I read in another question that the Real Time Clock crystal might be at fault, does that seem to be the case here?

Custom built machine with a Gigabyte GA-770TA-UD3 motherboard and a AMD Phenom 955 BE @3.2GHz running Windows 7.

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BIOS clocks are notoriously poor. That's even worse than average though... – Billy ONeal Jul 3 '11 at 4:35 – Aki Jul 3 '11 at 6:01
up vote 3 down vote accepted

I use an HP/Apollo system for work which is designed so that the clock runs slowly, but a modern PC motherboard shouldn't do this.

You could use an NTP server to synchronise the clock to a time standard, but it should be able to keep better time (than you're seeing) without it.

I would agree with the theory which says it's the RTC crystal. What you're seeing may be an indication it's about to fail completely.

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If it really is not the battery, I would have to believe you have a motherboard problem. Check out this link for more on board time problems:

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