Windows 7 Windows 7 time gets seriously behind

[Rafcio]

I have a PC (Window 7 Ultimate x64 SP1) with a time keeping problem. When Win7 is running the internal time gets behind 5 seconds every 10 minutes. This is a serious lag. The problem is pretty consistent. The system synchronizes its time every 10 minutes (because it is so inaccurate) with the atomic time servers and every synchronization interval the time is behind 5 seconds with just a few miliseconds variation between synchronization intervals. This is not a hardware problem, because when I boot the same system into XP maintenance partition the time is accurate. Actually, it is a few miliseconds ahead every 10 minutes, so this proves that there is nothing wrong with the motherboard. The problem is in Windows 7. From what I learned the time is kept internally by counting the hardware timer "ticks", so somehow Windows 7 is missing a lot of those ticks, while XP is OK in this respect. This problem happens regardless if W32Time service is running or not.
Has anybody seen this behavior and knows how to fix it, or is it a Windows bug?

 

[Saltgrass]

I don't think it is a Windows 7 bug, but it might be related to something going on in your system.

Have you checked your system time in the bios? That might start having problems if the CMOS battery is getting weak. As to how Windows 7 keep time, I do not know the details, but do you see anything in Event Viewer?

 

[cliffordcooley]

This is not a hardware problem, because when I boot the same system into XP maintenance partition the time is accurate. Actually, it is a few miliseconds ahead every 10 minutes, so this proves that there is nothing wrong with the motherboard. The problem is in Windows 7.

That proves nothing, system time is kept by the frequency of which your motherboard is operating. System time is kept even when the PC is shut down. The only way for an OS to effect system time, is for the motherboard frequency to slow down. Windows 7 maybe using more resources than XP causing your hardware to lag. Hardware lag would be a hardware problem not a problem with the OS.

 

[Pauli]

As simple as it may sound, check your CMOS battery.

 

[Rafcio]

The motherboard clock operates at the same frequency regardless of the OS booted. For me it looks like something under Win7 intercepts certain number of timer ticks before time keeping "service" in Windows can count them. That something must be operating at the kernel level, so most likely a hardware driver. How do I find out which drivers can be potentially intercepting timer ticks?

I replaced the motherboard in this system a couple of months ago with exactly the same model and the problem didn't go away. It has been present in this system from the very beginning (about a year now). While it is certainly possible the problem is hardware-based, it looks very unlikely to me to be such.

Also, this is temporarily a remote system for me and I won't have a physical access to it to replace the CMOS battery until Thanksgiving.

The system log is clean and it has information level messages every 10 minutes that the time has been set (by the time sync program).