Video Cables – CompTIA A+ 220-1101 – 3.1

There’s more than one way to connect a video output device. In this video, you’ll learn about VGA, HDMI, DisplayPort, and DVI cables.

A video format that’s been around for a very long time is the VGA type connector. That stands for Video Graphics Array. The connector itself is a DB-15, connector although technically that particular size is a DE-15, but very often we just refer to this as a DB-15 connector.

This connector is also a very unique blue color. That blue color is associated with VGA in the PC System Design Guide Standards. This is a standard that supports video displays, but it has no way to integrate audio signals within this video connection. So if you are connecting a monitor using a VGA connection and you need audio output, you’ll need to have a separate audio connection from that device.

Unlike some of our newer video standards, this VGA signal is an analog signal. So as you extend this VGA signal beyond 5 to 10 meters, you’ll see that the screen becomes fuzzier and more difficult to see as that signal degrades.

The VGA connector on the back of a computer is a 15 pin connector, and it’s a relatively unique connector. You don’t see other devices using this 15 pin connector. So whenever you see that connector type, you can automatically assume that’s a VGA connection.

A more modern type of video connection is the HDMI connector or High Definition Multimedia Interface. This is a digital connection that not only includes the video signal but can also incorporate audio within that same cable. It’s not unusual to see HDMI cables extending around 20 meters before you start to have dropout and other digital artifacts appear on the screen. This common type A connector that you most often see with HDMI is a 19 pin connector and it is a proprietary type specific to HDMI. The only time you’ll see this connector type being used is if you’re connecting to an HDMI interface.

Here’s the back of a video adapter. You can see that it does support HDMI output on this video adapter. This also supports DisplayPort interfaces DVI interfaces. We’ll look at those two types next.

DisplayPort is another video standard. It is a digital standard and is able to send packetized video and audio signals over these DisplayPort cables. There’s commonly two different types of DisplayPort interfaces you might see. The standard DisplayPort interface is shown here, and there’s a smaller mini DisplayPort interface that can also be used. If you’re using the larger DisplayPort interface, you’ll notice that there are hooks connected to this particular interface that lock that into place. So you can’t simply pull it out of a DisplayPort interface. You’ll need to push down on a release mechanism and then it can easily be removed from that DisplayPort interface.

DisplayPort is also passively compatible with HDMI. So if you have a computer with a DisplayPort interface and a monitor with an HDMI interface, you simply need a cable that has DisplayPort on one side and HDMI on the other and the compatibility between those two allows them to work perfectly.

Here’s a video adapter that has an HDMI output and DisplayPort outputs as well. You can see that the DisplayPort interfaces are shaped to be slightly different than the HDMI. This video card also has a DVI connector at the top as well and there are many types of DVI interfaces.

DVI stands for Digital Visual Interface. And there are many different types of interfaces in the DVI family. These allow you to send video signals over what we call single link and dual link. A single link connection supports 3.7 gigabits of throughput, which allows us to view definition television at 60 frames a second. Dual link connections have effectively twice as much throughput and allow us to view HD television at 85 frames per second.

DVI is a video connection only and does not pass any audio signals through the DVI connection. DVI supports both analog and digital connections. You can see an example of the DVI-A or analog connector here at the top. But there are also DVI-D or digital connections in here as well. You might even have a DVI-I, which is an integrated connection which allows for both digital and analog communication in the same connector. Here’s the end of a DVI cable. This happens to be a DVI digital cable on a single link connection, and that would connect to a corresponding interface on your video adapter card.

So now you should be able to look at the back of any video adapter and be able to immediately recognize what those video interfaces are. This particular card supports DisplayPort output, HDMI, and both a DVI integrated and DVI digital connection. You should also be able to find the cables themselves and quickly identify what type of connector it is. On this screen, we have a VGA connector, a DVI connector, and HDMI.