KnowledgeBase Archive

An Archive of Early Microsoft KnowledgeBase Articles

View on GitHub

Q171790: Time Incorrect After Restarting Multiprocessor System

Article: Q171790
Product(s): Microsoft Windows NT
Version(s): WinNT:3.51,4.00
Operating System(s): 
Keyword(s): kbenv kbWinNT400sp4fix
Last Modified: 09-AUG-2001

-------------------------------------------------------------------------------
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 kbWinNT400sp4fix 
Technology        : kbWinNTsearch kbWinNTWsearch kbWinNTW400 kbWinNTW400search kbWinNT351search kbWinNT400search kbWinNTW351search kbWinNTW351 kbWinNTSsearch kbWinNTS400search kbWinNTS400 kbWinNTS351 kbNTTermServ400 kbNTTermServSearch kbWinNTS351search
Version           : WinNT:3.51,4.00
Issue type        : kbbug
Solution Type     : kbfix

=============================================================================

THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY.