about clock

[cutty]

I downloaded a small program which can get accurate time from NIST and adjust system time. I found the time in one of my system is always inaccurate. After I adjust the time, leave the system on and do nothing, when I try again, it would already be 20 seconds difference. My other two computers will have only few seconds difference after a day. The one which is always inaccurate is an AMD XP2200+ with NFORCE2 motherboard, the other two are P4-1.8 and PM-1.6. Do you have any clue what may be the cause for the time error? Thank you.

 

[n0cmonkey]

CMOS battery needs to be replaced?

Run a good ntp program on there more often than a day and you shouldn't have any problems.

 

[The J]

Maybe your CMOS battery is dying? If you've had the computer for a few years, try replacing it. Even if the battery isn't dead, it won't hurt to replace it and the battery is only about $3. Most motherboards I've seen use a CR2032 disc battery.

 

[cutty]

Thank you. However I heard that if the system is on, then it shouldn't depend on the battery, is that true?

 

[whatsyourdeal]

If you leave your computer on all day or for a long period of time, you may notice that the Windows clock on the Taskbar may lose time, perhaps two minutes per day, or perhaps an hour or more. This can occur for various reason, as explained in the following Microsoft Knowledge Base article:

http://support.microsoft.com/default.aspx?scid=kb;en-us;189706
Windows Clock on Taskbar and in Date/Time Tool Loses Time

The time of day is maintained by a battery charging the CMOS. One reason for a time loss could be the running down of the battery. Since the CMOS does maintain the correct time (if you restart the computer, the Windows clock is updated), you can determine if the problem is a weak battery in this way: click on the Start button, select Programs from the Start Menu, and click the entry for MS-DOS Prompt. At the DOS prompt, type the command TIME and press the Enter key. If the time reported by the TIME command differs from that on the Windows clock on the Taskbar, you should replace the computer's battery. Type EXIT and press the Enter key to exit the MS-DOS Prompt session and return to Windows.

There are other reasons why the Windows clock may lose time. For example, if you have Advanced Power Management settings enabled in your computer's BIOS, rather than in Windows, this may interfere with the Windows time. It can also happen with some third-party antivirus programs, utilities, and screen savers.

In order to let Windows control Advanced Power Management, you click on the Start button, point to Settings on the Start Menu, and click Control Panel. Double click the Power Management icon, select your desired settings and click OK.

Hope this helps

 

[n0cmonkey]

Every consumer computer's clock is off. They'll all be off to varying degrees. Replace to CMOS battery to see if that helps. A good Network Time Protocol program is a godsend.

 

[dullard]

Very interesting read. I'm not typing another post about computer clocks. Search for my name and clock if you want.

 

[cutty]

Thank you very much!!!

 

[JimPhelpsMI]

HI, There are two clocks involved. The battery clock on the MB is loaded into the Software clock on boot. If the big diff is when the machine is off and unplugged from the wall outlet (ATX only) the Batt clock is off. Not many are accurate and some are way off. A bad battery will dump the entire time not just a few seconds. If the diff is while the machine is running it's the software clock which is clocked off the MB real time clock. I use an old DOS program call FIXCLOCK.EXE that adjusts the batt clock on boot on MBs that are way off. Many years ago the MB had a variable cap to adjust the clock, but no more. Jim