DVI and HDMI compatibility
HDMI is a newer digital audio/video interface developed and promoted by the consumer electronics industry. DVI and HDMI have the same electrical specifications for their TMDS and VESA/DDC links. However, HDMI and DVI differ in several key ways:
HDMI lacks VGA compatibility. The necessary analog contacts are absent in HDMI connectors.
DVI is limited to the RGB color range (0-255). HDMI supports RGB, but also supports YCbCr 4:4:4 and YCbCr 4:2:2. These ranges are widely used outside of (beyond) computer graphics, color rendering.
HDMI supports the transport of packets, needed for digital audio, in addition to digital video. An HDMI source differentiates between a legacy DVI display and an HDMI-capable display by reading the display's EDID block.
To promote interoperability between DVI-D and HDMI devices, HDMI source components and displays support DVI-D signalling. For example, a 1080p HDMI display can be driven by a single-link DVI-D source - since HDMI and DVI-D both define an overlapping minimum set of supported resolutions and frame buffer formats. So, DVI-D devices output HDMI signals, many including audio, (examples: ATI 3000-series and NVIDIA GTX 200-series video cards),[9] and some multimedia displays input that HDMI signal, including audio, by using a DVI to HDMI adapter. Exact capabilities vary by video card specifications.
In the reverse scenario, a DVI monitor that lacks optional support for HDCP might be unable to display protected content, even though it is otherwise compatible with the HDMI source. And, features specific to HDMI, such as: remote-control, audio transport, xvYCC, and deep-color, are not usable in devices that support only DVI signals. Effectively, HDCP compatibility between source and destination devices is completely subject to the manufacturer's specifications for each, respective HDMI capable device.