The Xv support only works when your XFree86 server supports your particular graphics card. If it works, then the frames per second value will be much higher. I don't have a complete list, but at least the Matrox Millenium G200 can be used with XFree86 V. 4.0.1. The Matrox Millenium II does not work. Check the XFree86 website and mailing list for more information and support. With the G200 and XFree86 4.0.1, the screen depth must be set to either 16 or 24 bits. If using 24 bits, the screen size must be no more than 1024 * 768.