Time Incorrect After Restarting Multiprocessor System

ID: Q171790

The information in this article applies to:

Microsoft Windows NT Workstation versions 3.51, 4.0
Microsoft Windows NT Server versions 3.51, 4.0
Microsoft Windows NT Server version 4.0, Terminal Server Edition

SYMPTOMS

On a multiprocessor computer, if you synchronize the system time to an external time source using the Date/Time tool in Control Panel, and then restart your system, the system time will be slow by four to five seconds for every processor after the first processor.

Example:

If you set the time on a 4-processor system, the system time will be 12-15 seconds slow (3 x 4-5 seconds). Note that the time loss is not cumulative; the system will still be slow by the same amount after another restart unless the time is changed again.

CAUSE

During system initialization, the system starts by using only one processor. The system time is retrieved from the system Real Time Clock (RTC) and loaded into the system clock. Later in the initialization process, the system clock timer is halted for four to five seconds while each additional processor is configured. This halting causes a time slip from the RTC value. When the time is written, it is written to both the system clock and to the RTC.

RESOLUTION

To work around this problem, perform one of the following:

Synchronize the system time with an external source and restart. Determine how much time the system lost during startup, and set the system time fast by this amount. After a restart, the time should be correct. You will need to repeat this procedure every time the system time is set.

Run the time service provided in the resource kit. This will keep a group of servers in sync with each other.

To resolve this problem, obtain the latest service pack for Windows NT 4.0 or Windows NT Server 4.0, Terminal Server Edition. For additional information, please see the following article in the Microsoft Knowledge Base:

Q152734 How to Obtain the Latest Windows NT 4.0 Service Pack

STATUS

Microsoft has confirmed this to be a problem in Windows NT 4.0 and Windows NT Server 4.0, Terminal Server Edition. This problem was first corrected in Windows NT 4.0 Service Pack 4.0 and Windows NT Server 4.0, Terminal Server Edition Service Pack 4.

Microsoft has confirmed this to be a problem in Windows NT version 3.51. We are researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.

Keywords : kbenv NT4SP4Fix kbbug4.00 kbfix4.00.sp4 kbbug3.51 ntmp NTSrvWkst
Version : WinNT:3.51,4.00
Platform : winnt
Issue type : kbbug