A way to solve the problem of system clock drift on the ASUS A7N8X Deluxe motherboard.
I bought an ASUS A7N8X Deluxe Rev. 2.0 motherboard in October 2003. The BIOS shows the following on boot.
Asus A7N8X 2.0 DELUXE UAY2 BIOS 2.00-D01 ACPI BIOS Rev 1008 08-04-2004-nVidia-nForce-A7N8X2.0
About February 2006, I started noticing the system clock (in Windows XP SP2) going faster than normal. It seemed move forward by multiple minutes every day. At first I thought it was a dying CMOS battery, but that would cause the clock to reset, not go faster. I installed the latest nForce2 chipset drivers from the Nvidia website. I also had flashed recently to the latest, non-beta BIOS from Asus.
Hunting around in some forums, I found an article that said to go into my BIOS and disable "APIC Mode". I tried this, but then Windows XP would not boot. I found another forum that mentioned setting the FSB Spread Spectrum to Disabled. I went into the BIOS and changed it from 0.50% to Disabled, and now my system clock keeps time normally. I'm not a hardware guy, so I have no idea why this works.
BTW, I use a utility called TClock to replace my standard system clock. This allows me to customize the display to show the day of the week and seconds, among other things. I also set the NTP server to timex.usg.edu, and can synchronize by simply right-clicking on the clock.