Looking to get hooked up?  A guide to VGA, DVI, and HDMI cables

April 4 2008

If you go to plug in your monitor and are perplexed by multiple ports on the back of your PC, you’re not alone. Monitor connectors, like most things PC, are in transition between old and new technologies. You may have one or the other, or both. Here’s a field-guide:

image VGA (Video Graphics Array), known to many as “the blue port,” is the old guard. VGA cables use analog (pre-digital) signals to connect your computer’s graphics card to an analog display, like an older cathode-ray tube (CRT)monitor.

Today, however, flat-screen LCD monitors have elbowed out CRTs. Being digital creatures themselves, LCDs are happier getting their input from a digital-friendly graphics card, via a digital cable. So the blue port now typically shares space with a newcomer: the DVI (Digital Video Interface) port, also called “the white one.”

imageDVI cables allow your computer to send pixel-by-pixel information to your LCD monitor, ensuring that each dot on the screen displays exactly as intended. These new connectors come in three flavors:

DVI-D (DVI-Digital): Carries purely digital data from end to end. Some DVI-D connectors (“dual-link”) have a few extra pins to push data through more quickly.

DVI-A (DVI-Analog): Takes digitalized data and puts it into a format usable by an analog display (for example, a high-resolution CRT monitor with a DVI-A port).

DVI-I (DVI-Integrated): Includes both modes.

If one end of your connection (PC or display) is DVI and the other is VGA, adaptors are available to bridge the divide at a minor cost in visual quality.

As DVI settles in, there’s also a new kid on the block:

imageHDMI (High-Definition Multimedia Interface) ports are appearing on some newer PCs. Out since around 2006, HDMI connectors are designed to carry high through-put digital signals between media-output devices (computers, DVD players, cable services) and large display devices like HDTVs.

HDMI cables carry the same data as DVI-D cables, but they also have several channels for audio and include anti-pirating mechanisms to protect copyrighted material.