Tech Files
The Lowdown on DVI, the Big Brother of Video Interfaces
The Silicon Image Company created Digital Video Interface, affectionately known as DVI, in order to have a simple Plug-and-Play standard for video hookups.
This all-digital, seemingly all-knowing connection automatically optimizes your computer to work with your monitor. You don't have to make minor adjustments to your monitor, or resolution or color changes to your computer—DVI handles it all, like the concierge at one of those really fancy hotels that you stay at while vacationing in the Bahamas on a company-paid junket.
[Ed.: Give it up, Roger! Mike'll never spring for it!]
While this is all just great in theory, there is a downside: DVI comes in several distinct flavors that you can't mix and match. If you want to use or service DVI hardware, you need to understand the differences among the various flavors (chocolate, vanilla swirl, stainless steel, etc.) and recognize their connectors.
DVI-D is a digital-only connector, and the most popular digital connector today. Looking at the picture below, you can see that it's an elongated female D-shaped connection with three evenly spaced rows of eight holes on the left two-thirds. On the right third of the interface is a horizontal rectangular slot, with a single hole above and below the slot aligned with its left edge.
A good way to recognize DVI-D among the various digital connectors is to tilt your head to the left—it's the only one that vaguely looks like a face ... with really tall hair. Check it out!
Figure 1: DVI-D connector
DVI-I can support both digital and analog inputs. As you can see, the connector looks identical to the DVI-D interface, except that it has two holes above and below the slot on the right side.
Figure 2: DVI-I connector
EVC (Enhanced Video Connector), also known as P&D (Plug and Display), is another connector type that some manufacturers use. This connector is similar to the DVI-I connector, but it's slightly larger in size; if you look closely you can also see that it has three rows of 10 pins each instead of 8. Like DVI-I, EVC supports both analog and digital inputs.
Figure 3: EVC (P&D) connector
DFP (Digital Flat Panel) was the initial connector type specified by the VESA (Video Electronics Standards Association) working group. Like DVI-D, this connector supports digital inputs only. While this connector type is still used on some displays, it is being phased out. Its interface is radically different from DVI-I, DVI-D, or EVC. The interface for DFP is a smaller D-shaped connection, with two widely spaced horizontal rows of 10 pins each.
Figure 4: DFP connector
That, as we say, is a wrap. Grab that new video card and flat panel monitor and plug them in!
- Roger Conrad