There is a mistake in this thread:
The GPU function only works in windows and not for linux or mac.Stuttering video while watching Flash, Silverlight (NetFlix) or DirectX Based Content in Boxee Beta.
To view smooth playing Flash, Silverlight and & HD content in Boxee Beta, a video card that supports GPU acceleration for all three types of media is required. To maximize this, the following updates should be considered where appropriate for Windows, Mac and Linux machines.
Your mileage may vary based on OS, hardware, drivers, local network and ISP connection speed.
* Adobe Flash 10.1 Beta- To use GPU acceleration in Boxee Beta with compatible video cards. Examples-Hulu, YouTube, etc.
o Flash Beta 10.1 - Windows, Mack, Linux
Windows-Install both ActiveX and Plug-in (32 and 64 bit)
Mac & Linux-Install the singe file listed.
Uninstall first any Adobe Flash programs before installing this update!