Bandwidth Impact Of ClearType In RDP - Revisited

Posted by bink on September 21 2007, 2:12 AM. Posted in Terminal Services.

Earlier Helge Klein wrote an interesting article on the subject of Windows Server 2008 Terminal Services Cleartype (Cleartype is about making fonts look nice and smooth on LCD screens) support and the effect it had on bandwidth usage. In this previous article Helge was able to determine that enabling ClearType could cost you three times the bandwidth. In a similar test Helge has tested the Cleartype bandwidth usage again, this time testing the impact of Cleartype on 16 bit sessions as well as 32 bit sessions. The results are actually quite surprising. Enabling font smoothing dramatically increases the bandwidth required for displaying text over RDP. The higher the color depth, the higher the toll payed for smooth fonts. While at 16 bits per pixel the factor is "only" 3.35, this number almost doubles when the color depth is changed to 32 bits. With 32 bits per pixel enabling font smoothing increases the bandwidth usage when displaying text by 6.6. Read the entire article here.