HDMI and DisplayPort

When deciding between HDMI and DisplayPort, the best choice depends largely on your specific use case.

High-Definition Multimedia Interface (HDMI) is a proprietary audio/video interface first introduced in December 2002 by a consortium of major electronics manufacturers, including Sony, Philips, Panasonic, and Toshiba. Its primary purpose was to create a unified standard for transmitting high-definition video and audio signals over a single cable,

streamlining the growing complexity of home entertainment systems. The first HDMI specification, version 1.0, was released with support for uncompressed video and up to eight channels of audio. Over the years, HDMI has undergone numerous revisions, with each iteration improving bandwidth, resolution, color depth, and additional features such as Ethernet and ARC (Audio Return Channel)1.

Pins

  • Pin 1 TMDS data2+
  • Pin 2 TMDS data2 shield
  • Pin 3 TMDS data2−
  • Pin 4 TMDS data1+
  • Pin 5 TMDS data1 shield
  • Pin 6 TMDS data1−
  • Pin 7 TMDS data0+
  • Pin 8 TMDS data0 shield
  • Pin 9 TMDS data0−
  • Pin 10 TMDS clock+
  • Pin 11 TMDS clock shield
  • Pin 12 TMDS clock−
  • Pin 13 Consumer Electronics Control (CEC)
  • Pin 14 Reserved (HDMI 1.0–1.3a) Utility/HEAC+ (HDMI 1.4+, optional, HDMI Ethernet Channel (HEC), and Audio Return Channel (ARC))
  • Pin 15 SCL (I2C serial clock for DDC)
  • Pin 16 SDA (I2C serial data for DDC)
  • Pin 17 Ground (for DDC, CEC, ARC, and HEC)
  • Pin 18 +5 V (up to 50 mA)
  • Pin 19 Hot plug detect (all versions) HEAC− (HDMI 1.4+, optional, HDMI Ethernet Channel, and Audio Return Channel)

By version 2.1, released in 2017, HDMI could handle 4K at 120Hz and 8K at 60Hz, supporting up to 48 Gbps of bandwidth with the Ultra High Speed HDMI cable. HDMI supports both video and multi-channel audio in a variety of formats. It transmits uncompressed digital video that can include standard, enhanced, or high-definition signals,

and in more recent versions, it supports 3D and dynamic HDR formats2. For audio, HDMI can transmit standard stereo, multichannel LPCM, DTS, and Dolby formats, including Dolby TrueHD and DTS-HD Master Audio3. HDMI’s video transmission adheres to TMDS (Transition-Minimized Differential Signaling),

a technology borrowed from DVI that enables reliable signal transmission with minimal noise. Communication over HDMI is not limited to just audio and video. It also includes several auxiliary channels. The Consumer Electronics Control (CEC) protocol allows devices to control each other via HDMI using a single remote control,

simplifying user interaction in multi-device setups. Additionally, HDMI Ethernet Channel (HEC) introduced with version 1.4 enables data sharing between HDMI-connected devices, reducing the need for separate Ethernet cables. HDMI is also known for its backward compatibility,

particularly with DVI. An HDMI-to-DVI adapter allows video transmission (but not audio), as both standards share the TMDS protocol, making HDMI an easy upgrade path for older DVI equipment.

DisplayPort, introduced later in 2006 by the Video Electronics Standards Association (VESA), was developed with a more computer-centric approach in mind. Unlike HDMI, which was designed with consumer electronics in focus, DisplayPort aimed to replace older PC video standards like VGA and DVI. Its royalty-free model encouraged adoption in the PC industry,

and its open standard allowed manufacturers to implement it without licensing fees. DisplayPort 1.0 offered up to 8.64 Gbps per lane and supported video resolutions up to 2560×1600. By the time DisplayPort 2.0 was announced in 2019, it offered massive bandwidth of up to 80 Gbps, far exceeding HDMI 2.1’s capabilities and enabling support for resolutions as high as 16K with HDR and high refresh rates.

Pins

  • Pin 1 ML_Lane 0 (p) Lane 0 (+)
  • Pin 2 GND Ground
  • Pin 3 ML_Lane 0 (n) Lane 0 (−)
  • Pin 4 ML_Lane 1 (p) Lane 1 (+)
  • Pin 5 GND Ground
  • Pin 6 ML_Lane 1 (n) Lane 1 (−)
  • Pin 7 ML_Lane 2 (p) Lane 2 (+)
  • Pin 8 GND Ground
  • Pin 9 ML_Lane 2 (n) Lane 2 (−)
  • Pin 10 ML_Lane 3 (p) Lane 3 (+)
  • Pin 11 GND Ground
  • Pin 12 ML_Lane 3 (n) Lane 3 (−)
  • Pin 13 CONFIG1 Connected to ground
  • Pin 14 CONFIG2 Connected to ground
  • Pin 15 AUX CH (p) Auxiliary channel (+)
  • Pin 16 GND Ground
  • Pin 17 AUX CH (n) Auxiliary channel (−)
  • Pin 18 Hot plug Hot plug detect
  • Pin 19 Return Return for power
  • Pin 20 DP_PWR Power for connector (3.3 V 500 mA)

DisplayPort excels in delivering high-resolution, high-refresh-rate video and supports multiple display streams through a single connector using Multi-Stream Transport (MST). It also supports both compressed and uncompressed audio formats similar to HDMI.

DisplayPort’s packet-based transmission protocol, modeled after PCI Express, differs from HDMI’s continuous signal. This allows for greater flexibility in signal routing, error correction, and data handling. In terms of communication, DisplayPort supports auxiliary channels used for link management and device communication, though it lacks an integrated Ethernet channel like HDMI.

Backward compatibility in DisplayPort is managed through adapters and dual-mode support. Devices with Dual-Mode DisplayPort (also known as DP++) can pass HDMI or DVI signals through a passive adapter, though this is typically limited to older versions and lower resolutions.

Unlike HDMI, DisplayPort does not natively support consumer electronics features like CEC, making it less suitable for home theater setups. When deciding between HDMI and DisplayPort, the best choice depends largely on your specific use case. HDMI is the go-to standard for consumer electronics such as TVs,

Blu-ray players, gaming consoles, and soundbars. It provides broad compatibility and integrated features like ARC and CEC that simplify home theater configurations. DisplayPort, on the other hand, is superior for high-performance computing environments where multi-monitor setups, high refresh rates, and ultra-high resolutions are essential, such as in gaming PCs or professional workstations. Its higher bandwidth capacity and support for daisy-chaining

displays through MST offer clear advantages for desktop setups. While both HDMI and DisplayPort continue to evolve and narrow the gap in features, DisplayPort remains favored in professional and PC gaming environments due to its bandwidth advantages and flexibility.

Conversely, HDMI’s ubiquity in the living room and its emphasis on integrated audiovisual convenience make it indispensable in consumer electronics. Ultimately, users should choose based on the devices they intend to connect and the performance requirements of their specific applications.

Footnotes
  1. Audio Return Channel (ARC) is a feature introduced in the HDMI 1.4 specification that allows audio to be sent from a television back to an audio system, such as a soundbar or AV receiver, using the same HDMI cable that normally delivers video to the TV. This eliminates the need for a separate audio cable (such as optical or coaxial) and simplifies setup by enabling two-way audio communication over a single HDMI connection. ARC supports most audio formats, including stereo and compressed surround sound like Dolby Digital and DTS, though for higher-quality uncompressed formats like Dolby TrueHD or DTS-HD Master Audio, the enhanced version called eARC (Enhanced Audio Return Channel), introduced with HDMI 2.1, is required. ARC also supports CEC (Consumer Electronics Control), which can allow one remote to control multiple devices over HDMI. ↩︎
  2. Dynamic HDR formats are advanced high dynamic range technologies that allow scene-by-scene or even frame-by-frame adjustments to brightness, contrast, and color for optimized visual quality. Unlike static HDR formats such as HDR10, which apply a single set of metadata for an entire video, dynamic HDR formats like Dolby Vision, HDR10+, and Advanced HDR by Technicolor use dynamic metadata to tailor the image output to the capabilities of the display and the content’s specific requirements. This results in a more accurate and vibrant viewing experience, especially in scenes with varying lighting conditions. These formats enhance details in both very bright and very dark areas and preserve color accuracy throughout. Dynamic HDR is supported over HDMI 2.1 and compatible with various 4K and 8K TVs, streaming platforms, and UHD Blu-ray discs. ↩︎
  3. Multichannel LPCM (Linear Pulse Code Modulation), DTS, and Dolby audio formats are widely used digital surround sound technologies that vary in compression and fidelity. LPCM is an uncompressed audio format that delivers high-quality sound across multiple channels, commonly used in Blu-ray discs and supported by HDMI for transmitting full-resolution audio without loss. DTS (Digital Theater Systems) and Dolby Digital are compressed formats that reduce file size while retaining good audio fidelity, typically using lossy compression. For higher fidelity, Dolby TrueHD and DTS-HD Master Audio are lossless formats that replicate studio-master quality, offering bit-for-bit accuracy and support for up to 7.1 channels (and beyond in some cases). These advanced formats are primarily found on Blu-ray discs and require HDMI connections to fully transmit their high-resolution audio data to compatible receivers or sound systems. ↩︎
Further Reading
Sources

Author: Doyle

I was born in Atlanta, moved to Alpharetta at 4, lived there for 53 years and moved to Decatur in 2016. I've worked at such places as Richway, North Fulton Medical Center, Management Science America (Computer Tech/Project Manager) and Stacy's Compounding Pharmacy (Pharmacy Tech).

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