by Paul Sanders
You've probably already noticed it. HDMI ports are being designed into more and more electronics, including portable devices like phones and cameras. Different HDMI versions are released as new capabilities are added by electronics manufacturers. Knowing a few facts about HDMI specifications will help you choose the right devices and HDMI A/V cables that will give you the best picture and sound capabilities for your computer, HDTV, video game console and home theater system.
An HDMI version is a standard for manufacturers. Electronics manufacturers design their devices to conform to the HDMI standard, so compatibility issues can arise when you try to connect devices and cables of an old HDMI version to devices designed for newer specifications.
Some HDMI features are optional for device makers. When a product displays a specific HDMI version number, it still might not support every single feature that the HDMI standard allows. Some of those features are optional. It's best to look for specifically listed features that your audio receiver or Blu-ray player supports, like 3D video support or different audio decoding, rather than assuming that it will have those features.
Color depth increases with newer versions. HDMI cables and devices transfer and display video data, encoding the colors as a digital signal for your TV or computer screen. Each pixel on the screen takes a certain amount of information, namely "bits," to describe the color it should be. The more bits per pixel, the more complex the colors can be, producing a richer picture quality. Older HDMI versions supported only supported 24 bits per pixel, while versions 1.3 and higher go all the way up to 40 bits per pixel.
Support for picture resolution and refresh rate differs between versions. Since HDMI cables are used to transfer sound and video to various devices, it needs to support different screen resolutions. Your computer monitor will probably support higher resolutions than your HDTV, for example. If your video source can produce it, the newest HDMI cables can transfer video at a resolution up to 4096 x 2160 pixels or more. But the higher you go with picture resolution, the slower the refresh rate tends to be, meaning your screen will refresh itself fewer times per second. Refresh rate does have some effect on picture quality.