Microsoft KB Archive/908929

= CPU usage is abnormally high when SAP processes use the new SAP flat memory model on a Windows Server 2003-based computer =

Article ID: 908929

Article Last Modified on 10/11/2007

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APPLIES TO


 * Microsoft Windows Server 2003 SP1
 * Microsoft Windows Server 2003, Datacenter Edition for Itanium-Based Systems
 * Microsoft Windows Server 2003, Enterprise Edition for Itanium-based Systems
 * Microsoft Windows Server 2003, Datacenter x64 Edition
 * Microsoft Windows Server 2003, Enterprise x64 Edition
 * Microsoft Windows Server 2003, Standard x64 Edition
 * Microsoft Windows Server 2003, Datacenter Edition (32-bit x86)
 * Microsoft Windows Server 2003, Enterprise Edition
 * Microsoft Windows Server 2003, Standard Edition (32-bit x86)
 * Microsoft Windows Server 2003, Web Edition

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SYMPTOMS
Consider the following scenario. On a Microsoft Windows Server 2003-based computer, you are running SAP. Additionally, the SAP processes use the new SAP flat memory model. In this scenario, the system experiences abnormally high CPU usage. For example, CPU usage may be 50 percent or more. This high CPU usage adversely affects computer performance.

Note This problem does not occur when SAP processes use the old hierarchical SAP memory model.



CAUSE
This problem occurs because the working set hash table is expanded in increments. However, these increments are too small. Therefore, the hash table expansion process is very resource-intensive.



Service pack information
To resolve this problem, obtain the latest service pack for Windows Server 2003. For more information, click the following article number to view the article in the Microsoft Knowledge Base:

889100 How to obtain the latest service pack for Windows Server 2003

Prerequisites
No prerequisites are required.

Restart requirement
You must restart the computer after you apply this hotfix.

Hotfix replacement information
This hotfix does not replace any other hotfixes.

File information
The English version of this hotfix has the file attributes (or later file attributes) that are listed in the following table. The dates and times for these files are listed in Coordinated Universal Time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time tool in Control Panel.

Windows Server 2003, x86-based versions


STATUS
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the &quot;Applies to&quot; section. This problem was first corrected in Windows Server 2003 Service Pack 2.



MORE INFORMATION
The latest deployed release of SAP introduces a flat memory model for 64-bit operating systems. In the earlier SAP model, SAP processes use a memory-mapped file to steadily map and unmap 1-megabyte (MB) segments. In the flat memory model, the memory-mapped file is replaced by shared memory. The flat memory model does not use the Map and Unmap calls that use serialized code in Windows. The flat memory model benefits high-end servers that use multicore processors. A throughput improvement of up to 10 percent has been measured when the flat memory model is used. For more information, click the following article number to view the article in the Microsoft Knowledge Base:

824684 Description of the standard terminology that is used to describe Microsoft software updates

Keywords: kbbug kbfix kbqfe kbpubtypekc kbhotfixserver kbwinserv2003presp2fix kbwinserv2003sp2fix KB908929

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