DisplayPort

DisplayPort (DP) is a digital display interface developed by a consortium of PC and chip manufacturers and standardized by the Video Electronics Standards Association (VESA). The interface is primarily used to connect a video source to a display device such as a computer monitor, and it can also carry audio, USB, and other forms of data.

DisplayPort was designed to replace VGA, FPD-Link, and Digital Visual Interface (DVI). The interface is backward compatible with other interfaces, such as HDMI and DVI, through the use of either active or passive adapters.

Overview

DisplayPort is the first display interface to rely on packetized data transmission, a form of digital communication found in technologies such as Ethernet, USB, and PCI Express. It permits the use of internal and external display connections, and unlike legacy standards that transmit a clock signal with each output, the DisplayPort protocol is based on small data packets known as micro packets, which can embed the clock signal within the data stream. This allows for higher resolution using fewer pins. The use of data packets also makes DisplayPort extensible, meaning additional features can be added over time without significant changes to the physical interface.

DisplayPort can be used to transmit audio and video simultaneously, although each is optional and can be transmitted without the other. The video signal path can range from six to sixteen bits per color channel, and the audio path can have up to eight channels of 24-bit, 192 kHz PCM audio that is uncompressed. A bi-directional, half-duplex auxiliary channel carries device management and device control data for the Main Link, such as VESA EDID, MCCS, and DPMS standards. In addition, the interface is capable of carrying bi-directional USB signals.

The DisplayPort interface uses an LVDS signal protocol that is not compatible with DVI or HDMI. However, dual-mode DisplayPort ports are designed to transmit a single-link DVI or HDMI protocol (TMDS) across the interface through the use of an external passive adapter. This adapter enables compatibility mode and converts the signal from 3.3 to 5 volts. For analog VGA/YPbPr and dual-link DVI, a powered active adapter is required for compatibility and does not rely on dual mode. Active VGA adapters are powered by the DisplayPort connector directly, while active dual-link DVI adapters typically rely on an external power source such as USB.

Versions

1.0 to 1.1

The first version, 1.0, was approved by VESA on 3 May 2006.<ref name="launch">Template:Cite web</ref> Version 1.1 was ratified on 2 April 2007,<ref>Template:Cite web</ref> and version 1.1a was ratified on 11 January 2008.<ref name="DP 1.1a">Template:Cite web</ref>

DisplayPort 1.0–1.1a allow a maximum bandwidth of 10.8Template:NbspGbit/s (8.64Template:NbspGbit/s data rate) over a standard 4-lane main link. DisplayPort cables up to 2 meters in length are required to support the full 10.8Template:NbspGbit/s bandwidth.<ref name="DP 1.1a" /> DisplayPort 1.1 allows devices to implement alternative link layers such as fiber optic, allowing a much longer reach between source and display without signal degradation,<ref>Template:Cite web</ref> although alternative implementations are not standardized. It also includes HDCP in addition to DisplayPort Content Protection (DPCP). The DisplayPortTemplate:Nbsp1.1a standard can be downloaded for free from the VESA website.<ref name="VESA Free Standards">Template:Cite web</ref>

1.2

DisplayPort version 1.2 was introduced on 7 January 2010.<ref name="DP 1.2 press">Template:Cite web</ref> The most significant improvement of the new version is the doubling of the effective bandwidth to 17.28Template:NbspGbit/s in High Bit Rate 2 (HBR2) mode, which allows increased resolutions, higher refresh rates, and greater color depth. Other improvements include multiple independent video streams (daisy-chain connection with multiple monitors) called Multi-Stream Transport, facilities for stereoscopic 3D, increased AUX channel bandwidth (from 1Template:NbspMbit/s to 720Template:NbspMbit/s), more color spaces including xvYCC, scRGB and Adobe RGB 1998, and Global Time Code (GTC) for sub 1Template:Nbspμs audio/video synchronisation. Also Apple Inc.'s Mini DisplayPort connector, which is much smaller and designed for laptop computers and other small devices, is compatible with the new standard.<ref name="ICCE" /><ref name="DevCon2010">Template:Cite journal</ref><ref name="GRAT583">Template:Cite web</ref><ref>Tony Smith, "DisplayPort revision to get mini connector, stereo 3D" Template:Webarchive, The Register, 13 January 2009</ref>

1.2a

DisplayPort version 1.2a was released in January 2013<ref>Template:Cite web</ref> and may optionally include VESA's Adaptive Sync.<ref>Template:Cite web</ref> AMD's FreeSync uses the DisplayPort Adaptive-Sync feature for operation. FreeSync was first demonstrated at CES 2014 on a Toshiba Satellite laptop by making use of the Panel-Self-Refresh (PSR) feature from the Embedded DisplayPort standard,<ref>Template:Cite web</ref> and after a proposal from AMD, VESA later adapted the Panel-Self-Refresh feature for use in standalone displays and added it as an optional feature of the main DisplayPort standard under the name "Adaptive-Sync" in version 1.2a.<ref>Template:Cite web</ref> As it is an optional feature, support for Adaptive-Sync is not required for a display to be DisplayPort 1.2a-compliant.

1.3

DisplayPort version 1.3 was approved on 15 September 2014.<ref name="DP 1.3 press">Template:Cite web</ref> This standard increases overall transmission bandwidth to 32.4Template:NbspGbit/s with the new HBR3 mode featuring 8.1Template:NbspGbit/s per lane (up from 5.4Template:NbspGbit/s with HBR2 in version 1.2), for a total data throughput of 25.92Template:NbspGbit/s after factoring in 8b/10b encoding overhead. This bandwidth is enough for a 4K UHD display (Template:Resx) at 120Template:NbspHz with 24Template:Nbspbit/px RGB color, a 5K display (Template:Resx) at 60Template:NbspHz with 30Template:Nbspbit/px RGB color, or an 8K UHD display (Template:Resx) at 30Template:NbspHz with 24Template:Nbspbit/px RGB color. Using Multi-Stream Transport (MST), a DisplayPort port can drive two 4K UHD (Template:Resx) displays at 60Template:NbspHz, or up to four WQXGA (Template:Resx) displays at 60Template:NbspHz with 24Template:Nbspbit/px RGB color. The new standard includes mandatory Dual-mode for DVI and HDMI adapters, implementing the HDMITemplate:Nbsp2.0 standard and HDCPTemplate:Nbsp2.2 content protection.<ref>Template:Cite web</ref> The Thunderbolt 3 connection standard was originally to include DisplayPortTemplate:Nbsp1.3 capability, but the final release ended up with only version 1.2. The VESA's Adaptive Sync feature in DisplayPort version 1.3 remains an optional part of the specification.<ref>Template:Cite web</ref>

1.4

DisplayPort version 1.4 was published 1 March 2016.<ref name="DP 1.4 press">Template:Cite web</ref> No new transmission modes are defined, so HBR3 (32.4Template:NbspGbit/s) as introduced in version 1.3 still remains as the highest available mode. DisplayPortTemplate:Nbsp1.4 adds support for Display Stream Compression 1.2 (DSC), Forward Error Correction, HDR10 metadata defined in CTA-861.3, including static and dynamic metadata and the Rec. 2020 color space, for HDMI interoperability,<ref>Template:Cite web</ref> and extends the maximum number of inline audio channels to 32.<ref name="VESAupdateDSC12">Template:Cite web</ref>

DSC is a "visually lossless" encoding technique with up to a 3:1 compression ratio.<ref name="DP 1.4 press"/> Using DSC with HBR3 transmission rates, DisplayPortTemplate:Nbsp1.4 can support 8K UHD (Template:Resx) at 60Template:NbspHz or 4K UHD (Template:Resx) at 120Template:NbspHz with 30Template:Nbspbit/px RGB color and HDR. 4K at 60Template:NbspHz 30Template:Nbspbit/px RGB/HDR can be achieved without the need for DSC. On displays which do not support DSC, the maximum limits are unchanged from DisplayPortTemplate:Nbsp1.3 (4K 120Template:NbspHz, 5K 60Template:NbspHz, 8K 30Template:NbspHz).<ref>Template:Cite web</ref>

1.4a

DisplayPort version 1.4a was published in April 2018.<ref name="DP 1.4a FAQ">Template:Cite web</ref> VESA made no official press release for this version. It updated DisplayPort's DSC implementation from DSC 1.2 to 1.2a.<ref name="DSC Display Stream Compression">Template:Cite web</ref>

2.0

According to a roadmap published by VESA in September 2016, a new version of DisplayPort was intended to be launched in "early 2017". It would have improved the link rate from 8.1 to 10.0Template:NbspGbit/s, a 24% increase.<ref>Template:Cite web</ref><ref>Template:Cite web</ref> This would have increased the total bandwidth from 32.4Template:NbspGbit/s to 40.0Template:NbspGbit/s.

However, no new version was released in 2017, likely delayed to make further improvements after the HDMI Forum announced in January 2017 that their next standard (HDMITemplate:Nbsp2.1) would offer up to 48Template:NbspGbit/s of bandwidth. According to a press release on 3 January 2018, "VESA is also currently engaged with its members in the development of the next DisplayPort standard generation, with plans to increase the data rate enabled by DisplayPort by two-fold and beyond. VESA plans to publish this update within the next 18 months."<ref>Template:Cite web</ref>

At CES 2019, VESA announced that the new version would support 8K @ 60Template:NbspHz without compression and was expected to be released in the first half of 2019.<ref>Template:Cite magazine</ref>

On 26 June 2019, VESA formally released the DisplayPort 2.0 standard. VESA stated that DP 2.0 is the first major update to the DisplayPort standard since March 2016, and provides up to a ≈3× improvement in data rate (from 25.92 to 77.37Template:NbspGbit/s) compared to the previous version of DisplayPort (1.4a), as well as new capabilities to address the future performance requirements of traditional displays. These include beyond 8K resolutions, higher refresh rates and high dynamic range (HDR) support at higher resolutions, improved support for multiple display configurations, as well as improved user experience with augmented/virtual reality (AR/VR) displays, including support for 4K-and-beyond VR resolutions.

Products incorporating DP 2.0 are not projected by VESA to appear on the market until late 2020.<ref name="DP 2.0 press">Template:Cite web</ref>

DP 2.0 configuration examples

With the increased bandwidth enabled by DP 2.0, VESA offers a high degree of versatility and configurations for higher display resolutions and refresh rates. In addition to the above-mentioned 8K resolution at 60Template:NbspHz with HDR support, DP 2.0 across the native DP connector or through USB-C as DisplayPort Alt Mode enables a variety of high-performance configurations:

• Single display resolutions
  • One 16K (15360 × 8640) display @ 60 Hz with 10 bpc (30 bit/px, HDR) RGB/Y′CBCR 4:4:4 color (with DSC)
  • One 10K (10240 × 4320) display @ 60 Hz and 8 bpc (24 bit/px, SDR) RGB/Y′CBCR 4:4:4 color (uncompressed)
• Dual display resolutions
  • Two 8K (7680 × 4320) displays @ 120 Hz and 10 bpc (30 bit/px, HDR) RGB/Y′CBCR 4:4:4 color (with DSC)
  • Two 4K (3840 × 2160) displays @ 144 Hz and 8 bpc (24 bit/px, SDR) RGB/Y′CBCR 4:4:4 color (uncompressed)
• Triple display resolutions
  • Three 10K (10240 × 4320) displays @ 60 Hz and 10 bpc (30 bit/px, HDR) RGB/Y′CBCR 4:4:4 color (with DSC)
  • Three 4K (3840 × 2160) displays @ 90 Hz and 10 bpc (30 bit/px, HDR) RGB/Y′CBCR 4:4:4 color (uncompressed)

When using only two lanes on the USB-C connector via DP Alt Mode to allow for simultaneous SuperSpeed USB data and video, DP 2.0 can enable such configurations as:<ref name="DP 2.0 press" />

• Three 4K (3840 × 2160) displays @ 144 Hz and 10 bpc (30 bit/px, HDR) RGB/Y′CBCR 4:4:4 color (with DSC)
• Two 4K × 4K (4096 × 4096) displays (for AR/VR headsets) @ 120 Hz and 10 bpc (30 bit/px, HDR) RGB/Y′CBCR 4:4:4 color (with DSC)
• Three QHD (2560 × 1440) @ 120 Hz and 8 bpc (24 bit/px, SDR) RGB/Y′CBCR 4:4:4 color (uncompressed)
• One 8K (7680 × 4320) display @ 30 Hz and 10 bpc (30 bit/px, HDR) RGB/Y′CBCR 4:4:4 color (uncompressed)

DP++

See DP++