Why Get an HD Video Card?

HD video cards, or more specifically, graphics cards that offer a High Definition Multimedia Interface (HDMI) output port, offer several advantages over graphics cards that only offer older Digital Visual Interface (DVI) output. These advantages are typically more valuable to a user who wants to connect a PC to a home theater, surround sound, or High-Definition Television (HDTV).

HDMI connections carry more types of information, and at a faster rate, than DVI connections. A single HDMI cable can carry all the following signals at once:

In comparison, a DVI cable can only carry a digital video signal. This means that a graphics card installed in a computer that only has DVI output cannot carry audio signals to the display device.

Computers and HDTV

For users who wish to connect their computer to an HDTV, a video card that is only equipped with DVI out will only be able to send video signals. If, say, the user wants to play back a Blu-ray disc on the computer, and have the signal transmitted to an HDTV, an additional audio line will be required to hear the audio playback.

In short, a computer without HDMI out cannot send both video and audio signals to the HDTV along a single wire.

Matters are further complicated if the HDTV is connected to a home theater or surround sound system. For this to work, the audio out from the computer must be connected to the audio in on the home theater system, while the DVI out must be plugged into a DVI-to-HDMI adapter, and them plugged into the HDTV.

If all of this sounds terribly complicated, then a graphics card with HDMI out is exactly what you need! By running a single HDMI line from the graphics card to the HDTV, both video and audio signals are free to travel down the cable, saving both time and hassle.

HDCP

High-bandwidth Digital Content Protection, or HDCP, is a digital copy-protection protocol originally developed by Intel.

HDCP is intended to halt and prevent the copying or unauthorized access of video or audio content as it travels across a data connection. Most commonly, this connection is HDMI, however HDCP also blocks content on DisplayPort and DVI connections.

HDCP is a finicky protocol, and often interacts poorly with technologies other than HDMI. For this reason, users who wish to interconnect a PC with a home theater system would be best served in ensuring that all connections are pure HDMI, with no DVI adapters between the computer that provides the content and the display devices that play the content.

In short, using a DVI out connection from a PC to and HDMI in connection on a HDTV has a tendency to invoke HDCP copyright protections on media that use this form of protection. It's best to stick with straight HDMI connections whenever possible to ensure that media is not inappropriately interrupted.

A Note on Cable Length: HDMI cables are sold in two varieties, "standard" and "high speed."

Standard or "Category 1" cables are certified to support video resolutions up to 1080x720, the normal resolution of an HDTV, and these cables are typically effective at lengths of no more than five meters. Longer lengths of category 1 cable may lead to single degradation or ghosting.

High speed or "Category 2" cables are certified to support resolutions up to 2160x1080, and can reach lengths of 15 meters before signal degradation or ghosting begin to occur.

In situations where longer cables are necessary, HDMI extenders can be utilized to prevent loss of signal en route to the display device. Users should be aware that HDMI extenders require an external power source, since they essentially act as an electronic signal booster along the data path. A single set of HDMI extenders will allow cable lengths of up to 30 meters, and an unlimited number of extenders can be utilized to provide an HDMI cable connection of any length.

CEC

The Consumer Electronics Control (CEC) is a feature of many HDMI compatible devices. CEC allows the user to centrally integrate and control all HDMI devices and appliances that share an HDMI connection.

While there are presently no graphics cards that offer drivers to support CEC functionality, both American Micro Devices (AMD) and Nvidia Corporation have announced plans to look in to offering CEC compliance on future generations of graphics cards.

This type of implementation would allow the user to control the computer and all attached HDMI devices via a single command interface, remote, or control panel, opening up a world of possibilities for home electronics integration.

Further, these drivers would likely be reverse compatible with presently existing graphics cards that have HDMI-out connections, meaning that future driver advances would allow retroactive upgrading of HDMI graphics cards to allow the integrations of computers into the home HDMI network.

For users with multiple HDMI devices and/or appliances, this is good news!

HD Video Card Summary

While HDMI-out is not a necessity for most PC gamers, computer users who have multiple HDMI devices or appliances would be best served in spending a few extra dollars and acquiring a graphics card with HDMI out.

Seamless integration with the home theater, lack of headaches from HDCP, and future plans for introducing the computer into the home HDMI network are all excellent reasons to aim for HDMI-out

.