For Windows Server 2008 and Windows Server 2008 R2

Navigate to Computer Configuration\Administrative Templates\Windows Components\Terminal Services\Terminal Server\Remote Session Environment and set compression algorithm for RDP data as follows:

Optimized to use less memory (RDP 5.2 or V1):

• Bulk compressor from Windows Server 2003

• Consumes more bandwidth than other compressors

• Has the least memory and CPU overhead

• Gives you the best server-side scalability

Balances network bandwidth and memory (RDP 6.0 or V2):

• The default setting if the Group Policy setting is not configured

• Balances between memory consumption and network bandwidth

• Can reduce your bandwidth by 5–30 percent compared to the RDP 5.2 compressor

Optimized to use less network bandwidth (RDP 6.1 or V3):

• A new compressor designed for Windows Server 2008

• Tuned to give you the best network performance

• Can reduce your bandwidth by 10–60 percent compared to the RDP 5.2 compressor

http://download.microsoft.com/download/4/d/9/4d9ae285-3431-4335-a86e-969e7a146d1b/RDP_Performance_WhitePaper.docx