Perhaps the most notable feature of G400 is its ability to drive two separate monitors to display a single desktop. This feature is known as "DualHead" and was a decisive edge for Matrox over the card's competitors at the time. The DualHead capability not only offered desktop widening but also desktop cloning (two screens showing the same thing) and a special "DVDMAX" mode which outputs video overlays onto the second monitor. Matrox's award-winning Powerdesk display drivers and control panel integrated Dualhead in a very flexible and functional way that become world-renowned for its effectiveness. However, contrary to the video mode's name, G400 does not support full DVD decoding hardware acceleration. G400 does have partial support for the DVD video decoding process but it does not perform inverse discrete cosine transform IDCT or motion compensation in hardware (the two most demanding steps of the process).