High Definition Multimedia Interface (HDMI) and DisplayPort are the latest in high-speed serial interfaces that transmit digital audio/video signals between electronic equipment via cables or extenders at high data rates. Though both are designed for carrying data-intensive HD audio and video – having replaced long-running but now antiquated analogue interfaces such as S-video, Video Graphics Array (VGA), and Component (RGB) – there exist major differences between HDMI and DisplayPort.
- With 19 pins, HDMI interface cables and extenders come in three sizes: standard HDMI (Type A) found on projectors, set-top boxes, TVs and laptops; a smaller mini-HDMI (Type B) for some tablet devices and laptops; and a micro-HDMI (Type C) on smart phones and tablets.
- With 20 pins, DisplayPort is available in two sizes: a full-sized standard, and the smaller, Apple-made Mini DisplayPort.
Resolution, Picture Quality & Bandwidth
- HDMI 1.4 cables and extenders support 4K video resolutions of up to 3840×2160 pixels at a refresh rate of 30 Hz, while bandwidth is capped at 10.2 Gbps. 1.4 is also limited to displaying 8-bit colour.
- However, the latest version – HDMI 2.0 – doubles the refresh rate to 60 Hz and increases the bandwidth to 18 Gbps. It also offers 10-bit or 12-bit colours with extended High Dynamic Range (HDR) capabilities.
- DisplayPort 1.2 supports 4K video resolutions of up to 3840×2160 pixels at a refresh rate of 60 Hz, with bandwidth capped at 17.28 Gbps.
However, the newest DisplayPort interface – version 1.3 – increases the supported video resolutions to 8K – up to 8192×4320 pixels. It also supports outputting video to two simultaneous 4K monitor displays – important for gaming. Its bandwidth is also increased to almost double at 32.4 Gbps. An Adaptive Sync feature helps maintain constant screen refresh rates by reducing instances of image tear during rapid, processor-demanding video sequences.