Matrox Graphics eXpansion Modules information

Matrox Graphics eXpansion Module (GXM) supports the use of multiple monitors over a single video source by splitting the output of a video source, providing an enlarged workspace or gaming environment. GXM is not a graphics card itself, and in fact requires a fairly powerful graphics card for playing games on multiple monitors.

While most modern graphics cards have support for dual monitors and can expand a desktop across three screens, 3D games were generally limited to a single monitor. The GXM uses the standard Extended Display Identification Data (EDID) structure to communicate its capabilities to the graphics card just as a monitor does. However, the GXM's resolution includes all pixels in the three monitors. If the TripleHead2Go were hooked up to three monitors with 800×600 resolution, the TripleHead2Go would report itself as a single monitor with 2400×600 resolution. The graphics card then sends out a 2400×600 signal which the TripleHead2Go divides and distributes to the appropriate monitors.