Types

• As of March of 2011, DVI is available in three types: digital only, known as DVI-D; analog only, or DVI-A; and digital and analog, known as DVI-I. The latter two are compatible with analog standards such as VGA and can transfer video information to ports using those standards with the appropriate adapter cables. There are five types of HDMI cable: two intended for home theater use, types A and B; two for portable devices, C and D; and one for automotive devices, E. None of these are compatible with older analog standards.
  
  

Quality

• The makers of HDMI derived the technology from the older DVI standard. As such the quality is identical, but only up to a point. At resolutions of 1920 by 1080 or less, there is no difference in quality between DVI and HDMI. However, above these resolutions, HDMI has an edge in that it supports resolutions up to 4096 by 2160. Compare this to DVI's maximum supported resolution of 2560 by 1600.
  
  

Cable

• Cable length can affect video quality of both DVI and HDMI. According to the website Home Theater, signal quality begins to deteriorate in cables longer than 15 feet. However, it is possible to compensate for this by increasing the thickness of the cable, measured by the unit AWG. The website HDMI vs DVI recommends a 26 AWG or greater for 20-foot cables; 24 AWG or greater for 25- to 50-foot cables; and 22 AWG for all cables over 75 feet.
  
  

Compatibility

• HDMI is backwards-compatible with DVI. This means that if you have two devices, one that uses HDMI and another that uses DVI, all you need is an HDMI to DVI cable and you'll be able to transfer information between the two. Note that this only works for video. HDMI only transfers audio information if both devices have HDMI ports.