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FIX: The WMV9 encoder performance on a multiprocessor system is severely impaired

This article has been archived. It is offered "as is" and will no longer be updated.
Consider the following scenario:
  • On a multiprocessor system, you encode a video by using one of the following:
    • Windows Media Encoder 9 Series
    • An application that is based on the Windows Media Format SDK
  • You compress the video by using one of the following:
    • The Windows Media Video v9 codec
    • The Windows Media Video 9 Advanced Profile codec
In this scenario, the WMV9 encoder performance is severely impaired.
This behavior is due to a bug in the Windows Media Video v9 encoder DirectX Media Object (DMO). The encoder sets an affinity for multiple instances of the DMO to the same single-processor core when the multiple instances are instantiated by the same caller thread.

Hotfix information

A supported hotfix is now available from Microsoft. However, it is intended to correct only the problem that is described in this article. Apply it only to systems that are experiencing this specific problem.

To resolve this problem, obtain the hotfix from the Microsoft Download Center.

Download information

The following files are available for download from the MicrosoftDownload Center.

Windows Vista, 32-bit versions (all languages)

DownloadDownload the Windows6.0-KB945170-x86.msu package now.

Windows Vista, 64-bit versions (all languages)

DownloadDownload the Windows6.0-KB945170-x64.msu package now.

Windows XP, x86-based versions

DownloadDownload the WindowsMedia11-KB945170-x86-INTL.exe package now.

Windows XP, x64-based versions

DownloadDownload the WindowsMedia11-KB945170-x64-INTL.exe package now.

Note This hotfix does not have a 64-bit version for Windows XP. This package installs the 32-bit version of this hotfix on the 64-bit version of Windows XP.

For more information about how to download Microsoft support files, click the following article number to view the article in the Microsoft Knowledge Base:
119591 How to obtain Microsoft support files from online services
Microsoft scanned this file for viruses. Microsoft used the most current virus-detection software that was available on the date that the file was posted. The file is stored on security-enhanced servers that help prevent any unauthorized changes to the file.

The global 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 item in Control Panel.

Windows Vista

File nameFile versionFile sizeDateTimePlatform

Windows XP

File nameFile versionFile sizeDateTimePlatform
Microsoft has confirmed that this is a bug in the Microsoft products that are listed in the "Applies to" section.
More information

Steps to reproduce the problem

  1. Install Windows Media Encoder 9 Series on a multiprocessor computer.
  2. Configure the encoder to encode a multi-bitrate video.
  3. Use a file as a source.
  4. Begin encoding.
  5. In Performance Monitor, notice that only one CPU is near 100 percent.
Note This is a "FAST PUBLISH" article created directly from within the Microsoft support organization. The information contained herein is provided as-is in response to emerging issues. As a result of the speed in making it available, the materials may include typographical errors and may be revised at any time without notice. See Terms of Use for other considerations.

Article ID: 945170 - Last Review: 01/16/2015 17:31:25 - Revision: 1.0

Windows Media Encoder 9 Series, Windows Media Encoder 9 Series x64 Edition, Windows Media Format 9.5 Software Development Kit

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