View Full Version : Fluctuating System Time

03-04-2003, 01:45 PM
I have a Compaq Proliant 1600 Server, which I had to replace the middle cage recently. The cage contains the system board that the processor and RAM slots into. This has allowed me to get the system back up and running. The replacement board was identical hardware to the removed one.

There has been one unfortunate side affect. The system time changes at either regular or semi-regular periods. The first change is random but each subsequent change moves the system time forward 7 years 175 days into the future. It does this about 8 times over the night.

Does anyone have any clues what might be happening? I have been shown that 7 years and 175 days approximates to 65535 hours which is the maximum you can move it forward in any one time?

If this was only happening at startup I'd be happy to suggest that the CMOS battery was dying. But as its doing these time jumps whilst running I am lost of ideas. Help?!?

Graham L
03-04-2003, 04:31 PM
It won't be the CMOS clock, because that has separate registers for century, year, hour, minute, second, and centisecond. Also, the CMOS clock is accessed only when the system boots. After that the OS maintains its own time. That is usually a "tick counter", (e.g. Unix time is defined as "seconds since Jan 1 1970". That used a 32 bit counter, which has recently overflowed. :D Modern Unix systems use a 64 bit counter which will overflow "one day in the future".

The fact that it keeps going forward suggests that it's happening in the "tick" interrupt which maintains the time.

I would be inclined to suspect a memory problem ( :_| ), but since you have movedp things, it might be connectors. Try unplugging and replugging everything.