HDMI vs DVI, what is the difference? Which one is better? Are DVI and HDMI compatible? And of course, given the choice, which one should you use? The differences (or lack there of) may surprise you. Lets take a look at each of them then evaluate the differences.
Digital Visual Interface (DVI) is a digital standard introduced in 1999 by the Digital Display Working Group (DDWG). It is designed primarily for carrying uncompressed digital video data to a display. Originally the display was a computer monitor but DVI is now commonly used for television as well. One of the main areas of confusion with DVI is the number of different connectors available, which represent different functionality. There are three main connection types for DVI, DVI-D (digital only), DVI-A (analog only) and DVI-I (digital & analog).
High-Definition Multimedia Interface (HDMI), released late in 2002, is an all-digital audio/video interface capable of transmitting uncompressed streams of data similar to DVI. However HDMI also provides the ability to carry audio signals, in addition to video, as well as incorporating HDCP, which is a Digital Rights Management technology.
So what is the difference?
When looking at the differences between HDMI and DVI we find they actually have more in common then differences. They both support digital transmission; they also are based on similar specifications since HDMI was derived from the DVI specification. There are two big differences:
HDMI incorporates content protection called High Definition Content Protection (HDCP).
HDMI supports audio in addition to digital video. (DVI only supports digital video)
Are DVI and HDMI compatible?
Is HDMI compatible with DVI? Since DVI is the predecessor to HDMI, HDMI and DVI are identical as far as video is concerned. Therefore, video backward compatibility exists. However, DVI will not support digital audio. For example, if you have an older DVI connection on your source and a HDMI connector on your display, a HDMI to DVI cable is all that is needed in order to view the video. A separate audio cable (TOSLINK or SPDIF) will be needed to carry the digital audio.
A Warning about Cable length
The HDMI specification does not define a maximum cable length. HDMI 1.3 defined two categories of cables: Category 1 (standard or HDTV) and Category 2 (high-speed or greater than HDTV) regardless, neither HDMI or DVI work well over distances greater then 15 feet. If you need a cable longer then 10 feet you will definitely want to consider top quality cables. For anything greater then 15 feet, some companies offer amplifiers, equalizers and repeaters that can help bridge longer distances.
Which one should I use today?
If available, we recommend HDMI. This is not because it is any better then DVI, only because the industry will heavily push HDMI due to the HDCP Digital Rights Management technology. However you should not expect any difference when moving from DVI to HDMI, therefore if you have DVI already, stick with it until the next standard comes around. A little off topic, but still of relevance is that you may be able to get similar quality video by using your existing Component connections. A common misconception is that Component cannot carry HDTV quality video, which is incorrect. Depending on the components in your system you may get the same or better performance with a Component connection then with a HDMI or DVI connection.