Speed Up File Copying in Windows Vista SP1 - While Playing Audio

Improving Network Performance in Windows Vista During Multimedia Playback

Windows Vista incorporates a limitation on network traffic, restricting it to 10 packets per millisecond during multimedia playback. This feature aims to prevent audio or video skipping. However, this restriction can significantly reduce network speeds, particularly on gigabit networks, especially when transferring files.

Service Pack 1 for Windows Vista introduced a registry modification that allows users to adjust the level of this throttling. This adjustment can partially alleviate the performance issue, but careful testing is crucial to avoid introducing audio stuttering.

Understanding the Setting

This setting is most beneficial when utilizing a gigabit network. The default configuration is generally adequate for wireless networks. Adjusting the setting on a wireless network may not yield noticeable improvements.

Manual Registry Modification

To implement this change, access the Registry Editor. This can be done by searching for "regedit.exe" in the Start Menu or Run dialog box.

Navigate to the following registry key:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Multimedia\SystemProfile

Within this key, locate the value named NetworkThrottlingIndex. This value can be modified to any integer between 1 and 70 (decimal).

Testing and Rebooting

It is recommended to experiment with different values for NetworkThrottlingIndex to determine the optimal setting for your specific network configuration.

A system reboot is required for the changes to take effect after modifying the registry value.

Further Resources

Additional information and testing results regarding this registry hack can be found on the Anandtech website. Their analysis includes graphical representations demonstrating the performance improvements.