Understanding DVI

DVI stands for Digital Video Interface. It is the newer, better video standard that is replacing the old 15 pin VGA connection, however it can get a little confusing. There are 3 basic types of DVI connections DVI-A (Analog) DVI-D (Digital) and DVI-I (Integrated) DVI-I supports both DVI-A and DVI-D. And all three of these types can have single link, and dual link connections. Dual link sends a second video channel, so it suports higher resoulutions and faster response time, but it is backward compatible.

As you can see, the six pins in the middle determine if the cable is dual link or single link. The 4 pins surrounding the wider “blade” make the difference between a DVI-D and DVI-I cable, and the DVI-A uses those 4 pins around the blade, but eliminates six of the other pins in the setup. I’ve never seen a dual link DVI-A, mostly I’ve only seen DVI-A cables for converting to VGA

DVI-D and DVI-A are not compatible. (the whole digital and analog battle) But individually they have their own plusses. For example a DVI-I or DVI-A port can be connected to A VGA monitor using a simple converter

DVI-D isn’t compatible with a VGA monitor or port, but will work with Digital Displays and HDTV’s or recievers. If you need to go from DVI-D to VGA, you can get a Digital to Analog Converter Which are quite a bit more expensive then an adapter. (But are often less expensive then replacing your display/projector/computer).

If you are buying, go with DVI-I whenever possible, it is the most compatible. But if you already have DVI products, and are trying to figure them out here are a few norms. (of course someone always will break the norm…but here’s a start)

The Easiest way to find out what you have, is to count the pins. If you have a pinout that matches any of the above images, then the matching cable should work. You can often find out more information from the user manual or technical documentation.

• Monitors generally use DVI-D for the DVI signal, however newer models support DVI-I so they can run off of a VGA port (using VGA resolutions)
• HDTV’s that have DVI ports seem to be almost exclusively DVI-D
• Projectors I have seen go both ways. Try checking the cable. If it comes with a VGA connection, then it is likely DVI-I or DVI-A. If it is a digital only projector it might only support DVI-D. The manufacturer documentation should have some additional information.
• Video Cards if they have all the holes, chances are that they are DVI-I. In many cases, replacing the Video card is the cheapest way to be able to connect to a new monitor or HDTV, We carry a Radeon card that has a DVI-I port, a VGA port and an S-Video port, and supports extended desktop (using the DVI and VGA ports)

You can see all of our DVI products, inluding our cables converters and Video Cards