Improving Remote Desktop Performance

If available network bandwidth between a client computer and the remote host computer is limited, you can improve a Remote Desktop experience by reducing the color depth on the Display tab of the RDC client from its default 32-bit value. You can also selectively disable desktop experiences on the Experience tab to further improve Remote Desktop performance.

If you routinely transfer large files, submit large print jobs, or perform other bandwidthintensive actions over a Remote Desktop connection, you may be able to improve the performance of a Remote Desktop experience by configuring display data prioritization on the host computer. Display data prioritization is designed to ensure that the screen performance aspect of a Remote Desktop experience is not adversely affected by such bandwidth-intensive actions. Display data prioritization works by automatically controlling virtual channel traffic between the client and host computer by giving display, keyboard, and mouse data higher priority than other forms of traffic.

The default setting for display data prioritization is to allocate 70 percent of available bandwidth for input (keyboard and mouse) and output (display) data. All other traffic, including use of a shared clipboard, file transfers, print jobs, and so on, is allocated by default only 30 percent of the available bandwidth of the network connection.

You can manually configure display data prioritization settings by editing the registry on a host computer running Windows Vista or later versions. The registry entries for display data prioritization are the following values, which are found under HKLM\SYSTEM\CurrentControlSet \Services\TermDD. (If these DWORD values are not present, you can create them.)

• FlowControlDisable Set this value to 1 to disable all display data prioritization and handle all requests on a first-in-first-out (FIFO) basis. The default value of this setting is 0.
• FlowControlDisplayBandwidth Specify a relative bandwidth priority for display and input data up to an allowed value of 255. The default value of this setting is 70.
• FlowControlChannelBandwidth Specify a relative bandwidth priority for all other virtual channels up to an allowed value of 255. The default value of this setting is 30.
• FlowControlChargePostCompression Determine whether flow control will calculate bandwidth allocation based on pre-compression bytes (if the value is 0) or postcompression bytes (if the value is 1). The default value for this setting is 0.

By default, the ratio of FlowControlDisplayBandwidth to FlowControlChannelBandwidth is 70 to 30 or 70:30. This means that 70 percent of available bandwidth is reserved for display and input traffic, and the remaining 30 percent will be used for other types of traffic. If your Remote Desktop experience is being degraded during large file transfers and other bandwidth-intensive activity, you might change FlowControlDisplayBandwidth to 85 and FlowControlChannelBandwidth to 15, which allocates 85 percent of available bandwidth for display and input traffic while reserving only 15 percent for other traffic.

Note You must reboot your host computer for these registry changes to take effect.