Specifications

Matrox Mura MPX Series – System Builder’s Guide 57
PCI Express
®
bandwidth considerations
in Matrox Mura MPX-based systems
System architecture is important in determining overall capture and display performance with
Mura-MPX based systems. Although the input resolutions and formats must be considered, the
system bus-level architecture also plays an important role in optimizing the system for the best
possible performance. This section will outline some of the issues to consider when implementing
Mura-MPX based display wall architectures.
Input source bandwidth requirements
Any capture architecture receives its data from external sources and transfers it to one or more
graphics engines for display. The inputs may take many forms: analog RGB, component video, DVI,
or even standard TV inputs using either composite or Y/C signals. Each of these inputs places a
different load on the system in terms of quantity of data to be transferred. Each input type is also
associated with a default data format: analog RGB and DVI are typically transferred in 24-bit RGB,
whereas composite and Y/C video data are generally transferred in 16-bit YUV. Understanding the
different transmission formats and their bandwidth requirements can help guide the integrator in
setting up and configuring a Mura-MPX based capture system.
The bandwidth required by any input source can be expressed as follows:
where the values
fps and Bytes Pixel represent the number of frames per second and the number of
bytes taken by each pixel, respectively. In analog RGB, component and DVI modes each pixel
generally requires 4 bytes. In TV modes (or when data is represented as 16-bit YUV data) each pixel
requires 2 bytes.
For example, a high-definition source being captured at 1920
× 1080p60 requires
of bandwidth.
An NTSC source at 60 Hz (interlaced) requires
of bandwidth.