DVI-Digital Video Interface

DVI is a popular video interface that can send digital or analog video between sources and displays. It is replacing VGA as the standard video connection between computers and monitors. There are several different versions of DVI, with differing compatibility.

The standard connection is DVI-D (Digital) It uses three rows of eight pins for dual link, or two groups of nine pins for single link. Both have a wide "blade" connector that can easily identify the port as DVI. This connection can send digital video only, it is not compatible with VGA, component or any other analog signals. The DVI-D connection is popular for the digital input on LCD monitors. DVI-D dual link is often used in home theater connections for HDTVs cable boxes or HD players. DVI-D single link can send an identical video signal to HDMI (without the audio).

DVI-A supports VGA signals with simple adapters or cables. There is no dual link version of DVI-A, however it can support resolutions higher than the 1920 x 1200 single link max. Note the 4 pins surrounding the wide blade connector. They are often referred to as the "Analog pins" and make up the red, green, and blue video signals, as well as one of the synch lines.

DVI-I (Integrated) can carry both digital and analog signals (though rarely at the same time). Most computer video cards will have DVI-I ports, and many projectors use DVI-I with support for digital or analog video. DVI-I also has the single and dual link variants.

Quality

Analog DVI is the same as VGA in regards to quality, distance limitations and responsiveness. Digital single link video can support resolutions up to 1920 x 1200. Dual link DVI-D can support higher resolutions (such as 2560x1600 used on 30" monitors)

Better than

Composite, S-Video and Component. VGA is the same as DVI-A transmission. HDMI is the same as DVI-D single link, but doesn't have the dual link or analog options (although HDMI does carry audio)

Applications

Increasingly popular on desktop computers, especially with add-on video cards. Video cards typically use the DVI-I variant, which can be easily converted to VGA or HDMI. Many LCD monitors now have both DVI-D (digital) and VGA monitor connections. Some older HDTV and HD players use the DVI connection. These are almost always DVI-D dual link connections, although only using single link (digital) video.

Conversions

Simple conversions require only a passive adapter or cable, there is no active conversion simply different pinouts of the same signals.

Complex conversions require active circuitry to convert the signal, to change it to the new signal. These often only work one-way.

Simple

• DVI-A or DVI-I to VGA in two adapters DVI-A F to VGA M and DVI-A M to VGA F also available as a DVI to VGA cable
• DVI-D to HDMI
• DVI-A or DVI-I to component Note, this is a passive adapter and ONLY works from a supported video card to a component display. DVI-A to component cables can be used from a component source to a projector as well.
• DVI-D to M1-D (M1 is a variant of DVI popular on Projectors)

Complex

• USB to DVI
• DVI-D to VGA
• Component to DVI-D
• DVI-D plus Audio to HDMI