DOCUMENT:Q169901 09-AUG-2001 [winnt] TITLE :Perfmon: Processor Spikes on Multiprocessor Computer PRODUCT :Microsoft Windows NT PROD/VER:winnt:3.51,4.0 OPER/SYS: KEYWORDS:kbbuglist ====================================================================== ------------------------------------------------------------------------------- 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 ------------------------------------------------------------------------------- SYMPTOMS ======== On a multiprocessor computer, you may see periods where the processor usage percentage will spike to 100 percent and back to 0 percent. This spike may happen for an unspecified period of time and then it may return to normal. This spike will happen on all processors in the computer at the same time. CAUSE ===== When Window NT queries a server for performance data, it uses a software timer that is shared among all the processors. On certain multiprocessor computers, this might report a time that is not properly synchronized with another processor. Therefore, the time counter occasionally becomes out of synch, causing the perfmon data to oscillate between a large positive and large negative number. This problem has only been seen, so far, on computers that are based on the Intel Multiprocessor Architecture. STATUS ====== Microsoft has confirmed this to be a problem in Microsoft Windows NT version 4.0. This problem was corrected in the latest Microsoft Windows NT 4.0 U.S. Service Pack. For information on obtaining the service pack, query on the following word in the Microsoft Knowledge Base (without the spaces): S E R V P A C K MORE INFORMATION ================ For the fix to work correctly, it must be able to determine that it should use the 8254 chip to use as its base timer. On newer BIOS, there will be a table entry that the HAL will look at while initializing. On computers without a newer BIOS, you will have to add a /USE8254 to the appropriate line in the Boot.ini file. Additional query words: peak peaks spike ====================================================================== Keywords : kbbuglist Technology : kbWinNTsearch kbWinNTWsearch kbWinNTW400 kbWinNTW400search kbWinNT351search kbWinNT400search kbWinNTW351search kbWinNTW351 kbWinNTSsearch kbWinNTS400search kbWinNTS400 kbWinNTS351 kbWinNTS351search Version : winnt:3.51,4.0 Hardware : ALPHA x86 Issue type : kbbug ============================================================================= 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. Copyright Microsoft Corporation 2001.