When you buy a new computer, it’s important to look at what type of output ports it supports. After all, you want to be able to easily hook it up to your computer monitor, or the projector at work or in school.
The reason most projectors, and even a lot of displays have multiple input ports is because there’s no clearcut standard for video connectors. In fact, there are multiple standards of computer video cables. Three of them are still actively competing for a spot on your laptop’s side. These are VGA, DVI and HDMI.
If you spend some time around computers, they may already look familiar. The purpose of this article is to teach you the difference between these three types of cables, both visually and technically.
VGA, or Video Graphics Array, is the most famous of the bunch. First produced in 1987, VGA has had plenty of time to get its roots down. Despite being slightly outdated, VGA is still featured on a lot of new computers because it’s the biggest thing the computer and display market has in terms of a computer video standard.
VGA cables carry an analog signal as opposed to a digital signal (ones and zeroes). Using higher frequencies, it’s possible to reach a relatively high range of video resolutions. However, video quality directly responds to cable quality, and doubly so on higher resolutions. Due to this, the quality of a VGA image can variate notable across different makes of cables.
The connector features fifteen pins spread over three horizontal rows and has a typical trapezoid shape, as you can see in the pictures above. Although computer and display fabricants are free in the design, the color blue is often associated with VGA ports and connectors.
DVI can be considered one of VGA’s successors, but although the connector is appearing more and more on computers and displays — especially on higher-end graphics card and high-resolution computer displays — DVI doesn’t have the mainstream fame that VGA does.
To make things more difficult, there are multiple types of DVI connectors. With exception of the least famous DVI-A connector, all of them work with uncompressed digital video. This means that the picture quality is not so heavily dependant on the quality of your cable; you either get a signal or you don’t. The difference is in the lay-out of the pins.
DVI-D is characterised by the single flat blade on one side of the connector, showing no pins above or below the blade. This can be seen in the screenshot above. DVI-D is for the sole transmission of digital video.
DVI-I looks very similar to DVI-D, but does have four pins surrounding the flat blade. These pins carry an analog signal, for compatibility with the VGA standard. This makes DVI-I connectors able to carry a digital and analog signal.
DVI-D and DVI-I connectors come in two additional flavours. Single-link, as demonstrated in the first picture, misses a section of pins in the middle of the connector. Dual-link connectors feature a single block of pins (three times eight), which allows to reach much higher resolutions.
More in-depth information and diagrams can be found on Wikipedia.
If DVI is the successor to VGA, HDMI is a possible successor to DVI. Possibly due to its appearance on high definition televisions, HDMI has known a quick rise to fame. Thanks to this compatibility with newer televisions, and its compact size compared to DVI, the HDMI connector is increasingly showing up in computers and computer displays as well.
HDMI, like DVI, is designed for the digital transmission of uncompressed data. However, besides a video signal, HDMI can also carry up to eight channels of compressed or uncompressed digital audio.
There are actually five HDMI connector types. The most famous one, type A, is what you’ll find in most of your appliances today. It’s also the connector we pictured above.
What video connectors do you have on your computer? Let us know in the comments section below the article!