Jul 11, 2012
“What’s the deal with all of the different video connectors on computers these days? VGA, DVI, HDMI, Thunderbolt — what’s the best, what should I use if my video card have different kinds of video ports and what kind of port should I look for on a new video card?”
VGA, DVI, HDMI, DisplayPort and Thunderbolt are the types of video connectors that you might find on a modern computer, and it pays to have a basic understanding of how to identify them and how they differ from one another because your computer’s video port determines whether you need to purchase an adapter to connect the computer to a television or other external display. The video port also influences the quality of your computer’s graphics to an extent. In this article, I’ll discuss the five most common computer video ports and describe how they differ.
A VGA port is trapezoidal in shape and has 15 pin holes. VGA is the only common monitor connection that uses an analog signal, and it is the standard connection for the large CRT monitors that all computers once used. Today, however, it is almost impossible to buy a new CRT monitor and virtually all new computers use flat-panel LCD displays. If you have an LCD monitor and a computer with a VGA port, you can connect the two using a VGA-to-DVI adapter, but be sure that you select the correct kind, such as female to male or male to female, depending on whether you will be connecting the two with a VGA cable or the DVI cable included with your monitor (either type of cable will work with the correct adapter).
The problem with connecting a modern LCD monitor to a VGA port is the fact that LCD monitors are digital, and VGA signals are analog. Before an LCD monitor can display an analog signal, it has to perform an analog-to-digital conversion, which will result in an image that isn’t as sharp as it could be. If you have an LCD monitor and a video card with both VGA and DVI ports, connect the monitor to the DVI port for the best possible image quality. If your video card only has a VGA port, think about picking up a cheap PCI, AGP or PCI Express video card with a DVI port; your eyes will thank you.
A DVI port has a wide rectangular shape with holes for up to 24 pins arranged in three groups of 8 on one side and a cross or plus shape on the other side. A DVI signal is digital, which means that it will produce perfect video quality with connected to a digital display such as an LCD monitor or high-definition television. DVI supports the encryption features required to play copy-protected high-definition content such as Blu-ray discs, and it supports the 1080p standard as well as even higher display resolutions. Most current computers and monitors have DVI ports, but some televisions do not. If you need to connect a DVI port to a television with an HDMI port, purchase a DVI-to-HDMI cable. The main drawback of DVI compared to HDMI is that it is a video-only technology; if you connect your computer to a television or other display with a DVI connector, you’ll need a separate audio cable for sound. Otherwise, DVI and HDMI are functionally similar.
An HDMI port has a small, somewhat trapezoidal shape. In the middle is a small card-shaped connector with several metal teeth that make contact with the teeth on an HDMI connector. The HDMI connection is small, convenient and has plenty of bandwidth — enough to support display resolutions even higher than DVI. HDMI also supports the transmission of digital audio over the same cable. HDMI is the connection you’ll find most often on modern game consoles, Blu-ray players and notebook computers. Many televisions have multiple HDMI ports, and monitors are increasingly coming equipped with HDMI ports as well. If your computer has an HDMI port, it is your best option for connecting an external display.
DisplayPort and Mini DisplayPort
DisplayPort and Mini DisplayPort are functionally identical to DVI, but smaller, making them common on notebook computers. Although Apple designed the DisplayPort interface, it has licensed the technology to other companies such as HP, Dell and Lenovo. The drawback of owning a notebook with a DisplayPort connection rather than an HDMI connection is the fact that many displays are not DisplayPort-compatible, which means you’ll need an adapter. DisplayPort-to-DVI and DisplayPort-to-HDMI adapters can be purchased online for less than $5.00. DisplayPort is more closely related to DVI than to HDMI; it does not carry audio signals.
Thunderbolt is a new connection developed by Apple and Intel to support both video and data transfer, in two directions simultaneously, over a single cable. Thunderbolt has massive data bandwidth; for example, you could connect an Apple Thunderbolt Display to your broadband modem, a FireWire hard drive, a USB audio device and an iPod or iPhone cradle, and then connect all of these devices to your computer through a single Thunderbolt connection between the monitor and computer. At present, only Apple computers have Thunderbolt ports. If the technology catches on, other computer manufacturers may license it. If you have a Thunderbolt display and need to connect it to a computer with an older Mini DisplayPort, you can use your existing adapters; Thunderbolt ports are the same size and shape — and are backwards-compatible with — Mini DisplayPort.
Some images courtesy of Wikipedia.