After you update your computer to Microsoft Windows XP Service Pack 2 (SP2), the performance of your 1394a or 1394b FireWire devices may be greatly decreased. A digital camera that uses S400 speed is an example of such a device.
This problem occurs if you connect a 1394a or 1394b FireWire device to a 1394b port. This problem occurs because Windows XP SP2 changes 1394b ports to S100 speed when you upgrade.
The following file is available for download from the Microsoft Download Center:
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
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To install this update, you must have Windows XP SP2 installed.
You must restart your computer after you install this update.
Update replacement information
This update is not replaced by any later hotfix or update.
Important This section, method, or task contains steps that tell you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. For more information about how to back up and restore the registry, click the following article number to view the article in the Microsoft Knowledge Base:
322756 How to back up and restore the registry in Windows
After you install this update, if you add a host controller for a new 1394 device to your computer, you must add or modify the SidSpeed entry in the Windows registry for the new 1394 host controller. To do this, follow these steps:
Click Start, click Run, type regedit, and then click OK.
Locate and then click the following registry subkey:
If the SidSpeed value does not exist in the right pane after you click the Device Parameters subkey in step 2, create it. To do this, point to New on the Edit menu, click DWORD Value, type SidSpeed, and then press ENTER.
Right-click SidSpeed, and then click Modify.
In the Value data box, type one of the values that are shown in the following table, and then click OK.
S400 speed (default value)
S400/S800 speed (Windows XP Service Pack 1 [SP1] value)
Note If you try to use a value that is larger than 3, SidSpeed will use a value of 0 (S100 speed).
Quit Registry Editor.
To locate the FireWire controller information, follow these steps:
Open Device Manager. To do this, right-click My Computer on the Start menu, click Manage, and then click Device Manager under System Tools. You can also click Properties under My Computer, and then click Device Manager on the Hardware tab.
Locate your FireWire controller in the IEEE 1934 Bus host controllers section.
Right-click the FireWire controller entry, click Properties, and then click the Details tab.
Click Device Instance Id. You see a string of letters and numbers that is similar to the following:
The information between the two slash marks (\) is the “1394_hc_hw_id". “VEN_104C&DEV_8020&SUBSYS_00D81028&REV_00” is the hardware ID in this example. The information that follows the second slash mark (\) is the “1394_instance_id”. “4&19FD8D60&0&60F0” is the instance ID in this example.
The English version of this update 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.
Date Time Version Size File name ----------------------------------------------------------------- 04-Nov-2004 20:59 5.1.2600.2549 6,656 Cstupd1394sidspeed.dll 04-Nov-2004 19:33 5.1.2600.2549 61,184 Ohci1394.sys
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
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