I have a WPF application that connects via a socket to a device and gets streaming text data (approx 1 message per second). This data is then displayed on the UI. The user can
FlowDocumentScrollViewers may have overhead due to the ability to display content in columns, etc. Is there a reason that a normal WPF RichTextBox won't work? Also, do you have .NET 3.5 SP1? The following link indicates that there have been big performance improvements for FlowDocuments in SP1: http://social.msdn.microsoft.com/Forums/en-US/wpf/thread/a116da54-ce36-446a-8545-3f34e9b9038d.