DisplayPort
DisplayPort is a digital display interface developed by a consortium of PC and chip manufacturers and standardized by the Video Electronics Standards Association. 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, Digital Visual Interface, and FPD-Link. 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, 192kHz 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 uses an LVDS signal protocol that is not compatible with DVI or HDMI. However, [|dual-mode] DisplayPorts are designed to transmit a single-link DVI or HDMI protocol across the interface through the use of an external passive adapter. This adapter enables compatibility mode and converts the signal from 3.3 volts 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. Version 1.1 was ratified on 2 April 2007, and version 1.1a was ratified on 11 January 2008.DisplayPort 1.0–1.1a allow a maximum bandwidth of 10.8Gbit/s over a standard 4-lane main link. DisplayPort cables up to 2 meters in length are required to support the full 10.8Gbit/s bandwidth. 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, although alternative implementations are not standardized. It also includes HDCP in addition to DisplayPort Content Protection. The DisplayPort1.1a standard can be downloaded for free from the VESA website.
1.2
DisplayPort version 1.2 was introduced on 7 January 2010. The most significant improvement of the new version is the doubling of the effective bandwidth to 17.28Gbit/s in High Bit Rate 2 mode, which allows increased resolutions, higher refresh rates, and greater color depth. Other improvements include multiple independent video streams called Multi-Stream Transport, facilities for stereoscopic 3D, increased AUX channel bandwidth, more color spaces including xvYCC, scRGB and Adobe RGB 1998, and Global Time Code for sub 1μs 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.1.2a
DisplayPort version 1.2a was released in January 2013 and may optionally include VESA's Adaptive Sync. 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 feature from the Embedded DisplayPort standard, 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. 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. This standard increases overall transmission bandwidth to 32.4Gbit/s with the new HBR3 mode featuring 8.1Gbit/s per lane, for a total data throughput of 25.92Gbit/s after factoring in 8b/10b encoding overhead. This bandwidth is enough for a 4K UHD display at 120Hz with 24bit/px RGB color, a 5K display at 60Hz with 30bit/px RGB color, or an 8K UHD display at 30Hz with 24bit/px RGB color. Using Multi-Stream Transport, a DisplayPort port can drive two 4K UHD displays at 60Hz, or up to four WQXGA displays at 60Hz with 24bit/px RGB color. The new standard includes mandatory [|Dual-mode] for DVI and HDMI adapters, implementing the HDMI2.0 standard and HDCP2.2 content protection. The Thunderbolt 3 connection standard was originally to include DisplayPort1.3 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.1.4
DisplayPort version 1.4 was published 1 March 2016. No new transmission modes are defined, so HBR3 as introduced in version 1.3 still remains as the highest available mode. DisplayPort1.4 adds support for Display Stream Compression 1.2, Forward Error Correction, HDR10 metadata defined in CTA-861.3, including static and dynamic metadata and the Rec. 2020 color space, for HDMI interoperability, and extends the maximum number of inline audio channels to 32.DSC is a "visually lossless" encoding technique with up to a 3:1 compression ratio. Using DSC with HBR3 transmission rates, DisplayPort1.4 can support 8K UHD at 60Hz or 4K UHD at 120Hz with 30bit/px RGB color and HDR. 4K at 60Hz 30bit/px RGB/HDR can be achieved without the need for DSC. On displays which do not support DSC, the maximum limits are unchanged from DisplayPort1.3.
1.4a
DisplayPort version 1.4a was published in April 2018. VESA made no official press release for this version. It updated DisplayPort's DSC implementation from DSC 1.2 to 1.2a.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 10.0Gbit/s, a 24% increase. This would have increased the total bandwidth from 32.4Gbit/s to 40.0Gbit/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 would offer up to 48Gbit/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."
At CES 2019, VESA announced that the new version would support 8K @ 60Hz without compression and was expected to be released in the first half of 2019.
On June 26, 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 compared to the previous version of DisplayPort, 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 support at higher resolutions, improved support for multiple display configurations, as well as improved user experience with augmented/virtual reality 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.
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 60Hz 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 display @ 60Hz with 10bpc RGB/ 4:4:4 color
- * One 10K display @ 60Hz and 8bpc RGB/ 4:4:4 color
- Dual display resolutions
- * Two 8K displays @ 120Hz and 10bpc RGB/ 4:4:4 color
- * Two 4K displays @ 144Hz and 8bpc RGB/ 4:4:4 color
- Triple display resolutions
- * Three 10K displays @ 60Hz and 10bpc RGB/ 4:4:4 color
- * Three 4K displays @ 90Hz and 10bpc RGB/ 4:4:4 color
- Three 4K displays @ 144Hz and 10bpc RGB/ 4:4:4 color
- Two 4K × 4K displays @ 120Hz and 10bpc RGB/ 4:4:4 color
- Three QHD @ 120Hz and 8bpc RGB/ 4:4:4 color
- One 8K display @ 30Hz and 10bpc RGB/ 4:4:4 color
Specifications
Main specifications
Main link
The DisplayPort main link is used for transmission of video and audio. The main link consists of a number of unidirectional serial data channels which operate concurrently, called lanes. A standard DisplayPort connection has 4 lanes, though some applications of DisplayPort implement more, such as the Thunderbolt 3 interface which implements up to 8 lanes of DisplayPort.In a standard DisplayPort connection, each lane has a dedicated set of twisted-pair wires, and transmits data across it using differential signaling. This is a self-clocking system, so no dedicated clock signal channel is necessary. Unlike DVI and HDMI, which vary their transmission speed to the exact rate required for the specific video format, DisplayPort only operates at a few specific speeds; any excess bits in the transmission are filled with "stuffing symbols".
In DisplayPort versions 1.01.4a, the data is encoded using ANSI 8b/10b encoding prior to transmission. With this scheme, only 8 out of every 10 transmitted bits represent data; the extra bits are used for DC balancing. As a result, the rate at which data can be transmitted is only 80% of the physical bitrate. The transmission speeds are also sometimes expressed in terms of the "Link Symbol Rate", which is the rate at which these 8b/10b-encoded symbols are transmitted. The following transmission modes are defined in version 1.01.4a:
- RBR : 1.62Gbit/s bandwidth per lane
- HBR : 2.70Gbit/s bandwidth per lane
- HBR2 : 5.40Gbit/s bandwidth per lane, introduced in DP1.2
- HBR3 : 8.10Gbit/s bandwidth per lane, introduced in DP1.3
- UHBR 10 : 10.0Gbit/s bandwidth per lane
- UHBR 13.5 : 13.5Gbit/s bandwidth per lane
- UHBR 20 : 20.0Gbit/s bandwidth per lane
- RBR: 4 × 1.62Gbit/s = 6.48Gbit/s bandwidth
- HBR: 4 × 2.70Gbit/s = 10.80Gbit/s bandwidth
- HBR2: 4 × 5.40Gbit/s = 21.60Gbit/s bandwidth
- HBR3: 4 × 8.10Gbit/s = 32.40Gbit/s bandwidth
- UHBR 10: 4 × 10.0Gbit/s = 40.00Gbit/s bandwidth
- UHBR 13.5: 4 × 13.5Gbit/s = 54.00Gbit/s bandwidth
- UHBR 20: 4 × 20.0Gbit/s = 80.00Gbit/s bandwidth
Audio data is transmitted across the main link during the video blanking intervals.
Auxiliary channel
The DisplayPort AUX channel is a half-duplex bidirectional data channel used for miscellaneous additional data beyond video and audio at the device manufacturer's discretion. AUX signals are transmitted across a dedicated set of twisted-pair wires. DisplayPort1.0 specified Manchester encoding with a 2Mbaud signal rate. DisplayPort1.2 introduced a second transmission mode called FAUX, which operates at 720Mbaud with 8b/10b encoding. This can be used to implement additional transport protocols such as USB2.0 without the need for an additional cable, but has seen little practical use as of 2018.Cables and connectors
Cables
Compatibility and feature support
All DisplayPort cables are compatible with all DisplayPort devices, regardless of the version of each device or the cable certification level.All features of DisplayPort will function across any DisplayPort cable. DisplayPort does not have multiple cable designs; all DP cables have the same basic layout and wiring, and will support any feature including audio, daisy-chaining, G-Sync/FreeSync, HDR, and DSC.
DisplayPort cables differ in their transmission speed support. DisplayPort specifies four different transmission modes which support progressively higher bandwidths. Not all DisplayPort cables are capable of all four transmission modes. VESA offers certifications for each level of bandwidth. These certifications are optional, and not all DisplayPort cables are certified by VESA.
Cables with limited transmission speed are still compatible with all DisplayPort devices, but may place limits on the maximum resolution or refresh rate available.
DisplayPort cables are not classified by "version". Although cables are commonly labeled with version numbers, with HBR2 cables advertised as "DisplayPort1.2 cables" for example, this notation is not permitted by VESA. The use of version numbers with cables can seem to imply that a DisplayPort1.4 display requires a "DisplayPort1.4 cable", or that features introduced in DP1.4 such as HDR or DSC will not function with older "DP1.2 cables", when in reality neither of these are true. DisplayPort cables are classified only by their bandwidth certification level, if they have been certified at all.
Cable bandwidth and certifications
Not all DisplayPort cables are capable of functioning at the highest levels of bandwidth. Cables may be submitted to VESA for an optional certification at various bandwidth levels. VESA offers three levels of cable certification: RBR, Standard, and DP8K. These certify DisplayPort cables for proper operation at the following speeds:In April 2013, VESA published an article stating that the DisplayPort cable certification did not have distinct tiers for HBR and HBR2 bandwidth, and that any certified standard DisplayPort cable—including those certified under DisplayPort1.1—would be able to handle the 21.6Gbit/s bandwidth of HBR2 that was introduced with the DisplayPort 1.2 standard. The DisplayPort1.2 standard defines only a single specification for High Bit Rate cable assemblies, which is used for both HBR and HBR2 speeds, although the DP cable certification process is governed by the DisplayPort PHY Compliance Test Standard and not the DisplayPort standard itself.
The DP8K certification was announced by VESA in January 2018, and certifies cables for proper operation at HBR3 speeds.
In June 2019, with the release of version 2.0 of the DisplayPort Standard, VESA announced that the DP8K certification was also sufficient for the new UHBR 10 transmission mode. No new certifications were announced for the UHBR 13.5 and UHBR 20 modes. VESA is encouraging displays to use tethered cables for these speeds, rather than releasing standalone cables onto the market.
It should also be noted that the use of Display Stream Compression, introduced in DisplayPort1.4, greatly reduces the bandwidth requirements for the cable. Formats which would normally be beyond the limits of DisplayPort1.4, such as 4K at 144Hz 8bpc RGB/4:4:4, can only be implemented by using DSC. This would reduce the physical bandwidth requirements by 2–3x, placing it well within the capabilities of an HBR2-rated cable.
This exemplifies why DisplayPort cables are not classified by "version"; although DSC was introduced in version 1.4, this does not mean it needs a so-called "DP1.4 cable" to function. HBR3 cables are only required for applications which exceed HBR2-level bandwidth, not simply any application involving DisplayPort1.4. If DSC is used to reduce the bandwidth requirements to HBR2 levels, then an HBR2-rated cable will be sufficient.
Cable length
The DisplayPort standard does not specify any maximum length for cables, though the DisplayPort 1.2 standard does set a minimum requirement that all cables up to 2 meters in length must support HBR2 speeds, and all cables of any length must support RBR speeds. Cables longer than 2 meters may or may not support HBR/HBR2 speeds, and cables of any length may or may not support HBR3 speeds.Connectors and pin configuration
DisplayPort cables and ports may have either a "full-size" connector or a "mini" connector. These connectors differ only in physical shape—the capabilities of DisplayPort are the same regardless of which connector is used. Using a Mini DisplayPort connector does not affect performance or feature support of the connection.Full-size DisplayPort connector
The standard DisplayPort connector was the sole connector type introduced in DisplayPort1.0. It is a 20-pin single-orientation connector with a friction lock and an optional mechanical latch. The standard DisplayPort receptacle has dimensions of 16.10mm × 4.76mm × 8.88mm.The standard DisplayPort connector pin allocation is as follows:
- 12 pins for the main link — the main link consists of four shielded twisted pairs. Each pair requires 3 pins; one for each of the two wires, and a third for the shield.
- 3 pins for the auxiliary channel — the auxiliary channel uses another 3-pin shielded twisted pair
- 1 pin for HPD — hot-plug detection pin
- 2 pins for power — 3.3V power and return line
- 2 additional ground pins —
Mini DisplayPort connector
The Mini DisplayPort connector is a 20-pin single-orientation connector with a friction lock. Unlike the full-size connector, it does not have an option for a mechanical latch. The mDP receptacle has dimensions of 7.50mm × 4.60mm × 4.99mm. The mDP pin assignments are the same as the full-size DisplayPort connector.
DP_PWR Pin
Pin 20 on the DisplayPort connector, called DP_PWR, provides 3.3V DC power at up to 500mA. This power is available from all DisplayPort receptacles, on both source and display devices. DP_PWR is intended to provide power for adapters, amplified cables, and similar devices, so that a separate power cable is not necessary.Standard DisplayPort cable connections do not use the DP_PWR pin. Connecting the DP_PWR pins of two devices directly together through a cable can create a short circuit which can potentially damage devices, since the DP_PWR pins on two devices are unlikely to have exactly the same voltage. For this reason, the DisplayPort1.1 and later standards specify that passive DisplayPort-to-DisplayPort cables must leave pin 20 unconnected.
However, in 2013 VESA announced that after investigating reports of malfunctioning DisplayPort devices, it had discovered that a large number of non-certified vendors were manufacturing their DisplayPort cables with the DP_PWR pin connected:
The stipulation that the DP_PWR wire be omitted from standard DisplayPort cables was not present in the DisplayPort1.0 standard. However, DisplayPort products did not begin to appear on the market until 2008, long after version 1.0 had been replaced by version 1.1. The DisplayPort1.0 standard was never implemented in commercial products.
Resolution and refresh frequency limits
The tables below describe the refresh frequencies that can be achieved with each transmission mode. In general, maximum refresh frequency is determined by the transmission mode. These transmission modes were introduced to the DisplayPort standard as follows:- RBR and HBR were defined in the initial release of the DisplayPort standard, version 1.0
- HBR2 was introduced in version 1.2
- HBR3 was introduced in version 1.3
- UHBR 10, UHBR 13.5, and UHBR 20 were introduced in version 2.0
In addition, individual devices may have their own arbitrary limitations beyond transmission speed. For example, NVIDIA Kepler GK104 GPUs support "DisplayPort 1.2" with the HBR2 transmission mode, but are limited to 540Mpx/s, only of the maximum possible with HBR2. Consequently, certain devices may have limitations that differ from those listed in the following tables.
To support a particular format, the source and display devices must both support the required transmission mode, and the DisplayPort cable must also be capable of handling the required bandwidth of that transmission mode.
Refresh frequency limits for standard video
Color depth of 8bpc is assumed for all formats in these tables. This is the standard color depth used on most computer displays. Note that some operating systems refer to this as "32-bit" color depth—this is the same as 24-bit color depth. The 8 extra bits are for alpha channel information, which is only present in software. At the transmission stage, this information has already been incorporated into the primary color channels, so the actual video data transmitted across the cable only contains 24 bits per pixel.Refresh frequency limits for HDR video
Color depth of 10bpc is assumed for all formats in these tables. This color depth is a requirement for various common HDR standards, such as HDR10. It requires 25% more bandwidth than standard 8bpc video.HDR extensions were defined in version 1.4 of the DisplayPort standard. Some displays support these HDR extensions, but may only implement HBR2 transmission mode if the extra bandwidth of HBR3 is unnecessary. Since there is no definition of what constitutes a "DisplayPort 1.4" device, some manufacturers may choose to label these as "DP 1.2" devices despite their support for DP 1.4 HDR extensions. As a result, DisplayPort "version numbers" should not be used as an indicator of HDR support.
Features
DisplayPort dual-mode (DP++)
DisplayPort pins | DVI/HDMI mode |
Main link lane 0 | TMDS channel 2 |
Main link lane 1 | TMDS channel 1 |
Main link lane 2 | TMDS channel 0 |
Main link lane 3 | TMDS clock |
AUX CH+ | DDC clock |
AUX CH− | DDC data |
DP_PWR | DP_PWR |
Hot-plug detect | Hot-plug detect |
Config 1 | Cable adapter detect |
Config 2 | CEC |
DisplayPort Dual-Mode, also called Dual-Mode DisplayPort, is a standard which allows DisplayPort sources to use simple passive adapters to connect to HDMI or DVI displays. Dual-mode is an optional feature, so not all DisplayPort sources necessarily support DVI/HDMI passive adapters, though in practice nearly all devices do. Officially, the "DP++" logo should be used to indicate a DP port that supports dual-mode, but most modern devices do not use the logo.
Devices which implement dual-mode will detect that a DVI or HDMI adapter is attached, and send DVI/HDMI TMDS signals instead of DisplayPort signals. The original DisplayPort Dual-Mode standard, used in DisplayPort1.1 devices, only supported TMDS clock speeds of up to 165MHz. This is equivalent to HDMI1.2, and is sufficient for up to 19201200 at 60Hz.
In 2013, VESA released the Dual-Mode 1.1 standard, which added support for up to a 300MHz TMDS clock, and is used in newer DisplayPort1.2 devices. This is slightly less than the 340MHz maximum of HDMI1.4, and is sufficient for up to 19201080 at 120Hz, 25601440 at 60Hz, or 38402160 at 30Hz. Older adapters, which were only capable of the 165MHz speed, were retroactively termed "Type1" adapters, with the new 300MHz adapters being called "Type2".
With the release of the DisplayPort1.3 standard, VESA added dual-mode support for up to a 600MHz TMDS clock, the full bandwidth of HDMI2.0. This is sufficient for 19201080 at 240Hz, 25601440 at 144Hz, or 38402160 at 60Hz. However, no passive adapters capable of the 600MHz dual-mode speed have been produced as of 2018.
Dual-mode limitations
- Limited adapter speed Although the pinout and digital signal values transmitted by the DP port are identical to a native DVI/HDMI source, the signals are transmitted at DisplayPort's native voltage instead of the 5V used by DVI and HDMI. As a result, dual-mode adapters must contain a level-shifter circuit which changes the voltage. The presence of this circuit places a limit on how quickly the adapter can operate, and therefore newer adapters are required for each higher speed added to the standard.
- Unidirectional Although the dual-mode standard specifies a method for DisplayPort sources to output DVI/HDMI signals using simple passive adapters, there is no counterpart standard to give DisplayPort displays the ability to receive DVI/HDMI input signals through passive adapters. As a result, DisplayPort displays can only receive native DisplayPort signals; any DVI or HDMI input signals must be converted to the DisplayPort format with an active conversion device. DVI and HDMI sources cannot be connected to DisplayPort displays using passive adapters.
- Single-link DVI only Since DisplayPort dual-mode operates by using the pins of the DisplayPort connector to send DVI/HDMI signals, the 20-pin DisplayPort connector can only produce a single-link DVI signal. A dual-link DVI signal uses 25 pins, and is therefore impossible to transmit natively from a DisplayPort connector through a passive adapter. Dual-link DVI signals can only be produced by converting from native DisplayPort output signals with an active conversion device.
- Unavailable on USB-C The DisplayPort Alternate Mode specification for sending DisplayPort signals over a USB-C cable does not include support for the dual-mode protocol. As a result, DP-to-DVI and DP-to-HDMI passive adapters do not function when chained from a USB-C to DP adapter.
Multi-Stream Transport (MST)
Daisy-chaining is a feature that must be specifically supported by each intermediary display; not all DisplayPort1.2 devices support it. Daisy-chaining requires a dedicated DisplayPort output port on the display. Standard DisplayPort input ports found on most displays cannot be used as a daisy-chain output. Only the last display in the daisy-chain does not need to support the feature specifically or have a DP output port. DisplayPort1.1 displays can also be connected to MST hubs, and can be part of a DisplayPort daisy-chain if it is the last display in the chain.
The host system's software also needs to support MST for hubs or daisy-chains to work. While Microsoft Windows environments have full support for it, Apple operating systems currently do not support MST hubs or DisplayPort daisy-chaining as of macOS 10.15.
DisplayPort-to-DVI and DisplayPort-to-HDMI adapters/cables may or may not function from an MST output port; support for this depends on the specific device.
MST is supported by USB Type-C DisplayPort Alternate Mode, so standard DisplayPort daisy-chains and MST hubs do function from Type-C sources with a simple Type-C to DisplayPort adapter.
High dynamic range (HDR)
Support for HDR video was introduced in DisplayPort1.4. It implements the CTA 861.3 standard for transport of static HDR metadata in EDID.Content protection
DisplayPort1.0 includes optional DPCP from Philips, which uses 128-bit AES encryption. It also features full authentication and session key establishment. Each encryption session is independent, and it has an independent revocation system. This portion of the standard is licensed separately. It also adds the ability to verify the proximity of the receiver and transmitter, a technique intended to ensure users are not bypassing the content protection system to send data out to distant, unauthorized users.DisplayPort1.1 added optional implementation of industry-standard 56-bit HDCP revision 1.3, which requires separate licensing from the Digital Content Protection LLC.
DisplayPort1.3 added support for HDCP2.2, which is also used by HDMI2.0.
Cost
VESA, the creators of the DisplayPort standard, state that the standard is royalty-free to implement. However, in March 2015, MPEG LA issued a press release stating that a royalty rate of $0.20 per unit applies to DisplayPort products manufactured or sold in countries that are covered by one or more of the patents in the MPEG LA license pool, which includes patents from Hitachi Maxell, Philips, Lattice Semiconductor, Rambus, and Sony. In response, VESA updated their DisplayPort FAQ page with the following statement:As of August 2019 VESA's official FAQ no longer contains a statement mentioning the MPEG LA royalty fees.
While VESA does not charge any per-device royalty fees, VESA requires membership for access to said standards. The minimum cost is presently $5,000 annually.
Advantages over DVI, VGA and FPD-Link
In December 2010, several computer vendors and display makers including Intel, AMD, Dell, Lenovo, Samsung and LG announced they would begin phasing out FPD-Link, VGA, and DVI-I over the next few years, replacing them with DisplayPort and HDMI. One notable exception to the list of manufacturers is Nvidia, who has yet to announce any plans regarding future implementation of legacy interfaces.DisplayPort has several advantages over VGA, DVI, and FPD-Link.
- Standard available to all VESA members with an extensible standard to help broad adoption
- Fewer lanes with embedded self-clock, reduced EMI with data scrambling and spread spectrum mode
- Based on a micro-packet protocol
- * Allows easy expansion of the standard with multiple data types
- * Flexible allocation of available bandwidth between audio and video
- * Multiple video streams over single physical connection
- * Long-distance transmission over alternative physical media such as optical fiber
- High-resolution displays and multiple displays with a single connection, via a hub or daisy-chaining
- * HBR2 mode with 17.28Gbit/s of effective video bandwidth allows four simultaneous 1080p60 displays, two 2560 × 1600 × 30 bit @ 120Hz, or 4K UHD @ 60Hz
- * HBR3 mode with 25.92Gbit/s of effective video bandwidth, using CVT-R2 timings, allows eight simultaneous 1080p displays @ 60Hz, stereoscopic 4K UHD @ 120Hz, or 5120 × 2880 @ 60Hz each using 24 bit RGB, and up to 8K UHD @ 60Hz using 4:2:0 subsampling
- Designed to work for internal chip-to-chip communication
- * Aimed at replacing internal FPD-Link links to display panels with a unified link interface
- * Compatible with low-voltage signaling used with sub-micron CMOS fabrication
- * Can drive display panels directly, eliminating scaling and control circuits and allowing for cheaper and slimmer displays
- Link training with adjustable amplitude and preemphasis adapts to differing cable lengths and signal quality
- * Reduced bandwidth transmission for cable, at least 1920 × 1080p @ 60Hz at 24 bits per pixel
- * Full bandwidth transmission for
- High-speed auxiliary channel for DDC, EDID, MCCS, DPMS, HDCP, adapter identification etc. traffic
- * Can be used for transmitting bi-directional USB, touch-panel data, CEC, etc.
- Self-latching connector
Comparison with HDMI
- In 2008, HDMI Licensing, LLC charged an annual fee of US$10,000 to each high-volume manufacturer and a per-unit royalty rate of US$0.04 to US$0.15. HDMI Licensing, LLC countered the "royalty-free" claim by pointing out that the DisplayPort specification states that companies can charge a royalty rate for DisplayPort implementation.
- DisplayPort 1.2 has more bandwidth at 21.6Gbit/s as opposed to HDMI 2.0's 18Gbit/s.
- DisplayPort 1.3 raises that to 32.4Gbit/s, and HDMI 2.1 raises that up to 48Gbit/s, adding an additional TMDS link in place of clock lane. DisplayPort also has the ability to share this bandwidth with multiple streams of audio and video to separate devices.
- DisplayPort has historically had higher bandwidth than the HDMI standard available at the same time. The only exception is from HDMI 2.1 having higher transmission bandwidth @48Gbit/s than DisplayPort 1.3 @32.4Gbit/s. DisplayPort 2.0 retook transmission bandwidth superiority @80.0Gbit/s.
- DisplayPort in native mode lacks some HDMI features such as Consumer Electronics Control commands. The CEC bus allows linking multiple sources with a single display and controlling any of these devices from any remote. DisplayPort 1.3 added the possibility of transmitting CEC commands over the AUX channel From its very first version HDMI features CEC to support connecting multiple sources to a single display as is typical for a TV screen. The other way round, Multi-Stream Transport allows connecting multiple displays to a single computer source. This reflects the facts that HDMI originated from consumer electronics companies whereas DisplayPort is owned by VESA which started as an organization for computer standards.
- HDMI can accept much longer max cable length than DisplayPort.
- HDMI uses unique Vendor-Specific Block structure, which allows for features such as additional color spaces. However, these features can be defined by CEA EDID extensions.
- Both HDMI and DisplayPort have published specification for transmitting their signal over the USB-C connector. For more details, see and List of devices with video output over USB-C.
Market share
Companion standards
Mini DisplayPort
Mini DisplayPort is a standard announced by Apple in the fourth quarter of 2008. Shortly after announcing Mini DisplayPort, Apple announced that it would license the connector technology with no fee. The following year, in early 2009, VESA announced that Mini DisplayPort would be included in the upcoming DisplayPort 1.2 specification.On 24 February 2011, Apple and Intel announced Thunderbolt, a successor to Mini DisplayPort which adds support for PCI Express data connections while maintaining backwards compatibility with Mini DisplayPort based peripherals.
Micro DisplayPort
Micro DisplayPort would have targeted systems that need ultra-compact connectors, such as phones, tablets and ultra-portable notebook computers. This standard would have been physically smaller than the currently available Mini DisplayPort connectors. The standard was expected to be released by Q2 2014.This project seems aborted to be replaced by DisplayPort Alt Mode for USB Type-C Standard.
DDM
Direct Drive Monitor 1.0 standard was approved in December 2008. It allows for controller-less monitors where the display panel is directly driven by the DisplayPort signal, although the available resolutions and color depth are limited to two-lane operation.Display Stream Compression
Display Stream Compression is a VESA-developed low-latency compression algorithm to overcome the limitations posed by sending high-resolution video over physical media of limited bandwidth. It is a visually lossless low-latency algorithm based on delta PCM coding and YCoCg-R color space; it allows increased resolutions and color depths and reduced power consumption.DSC has been tested to meet the requirements of ISO/IEC 29170-2 Evaluation procedure for nearly lossless coding using various test patterns, noise, subpixel-rendered text, UI captures, and photo and video images.
DSC version 1.0 was released on 10 March 2014, but was soon deprecated by DSC version 1.1 released on 1 August 2014. The DSC standard supports up to 3:1 compression ratio with constant or variable bit rate, 4:4:4 chroma subsampling, optional 4:2:2 conversion and 6/8/10/12 bits per color component.
DSC version 1.2 was released on 27 January 2016 and is included with DisplayPort 1.4; version 1.2a was released on 18 January 2017. The update includes native encoding of 4:2:2 and 4:2:0 formats in pixel containers, 14/16 bits per color, and minor modifications to the encoding algorithm.
DSC compression works on a horizontal line of pixels encoded using groups of three consecutive pixels for native 4:4:4 and simple 4:2:2 formats, or six pixels for native 4:2:2 and 4:2:0 formats. If RGB encoding is used, it is first converted to reversible YCgCo. Simple conversion from 4:2:2 to 4:4:4 can add missing chroma samples by interpolating neighboring pixels. Each luma component is coded separately using three independent substreams. Prediction step is performed using one of the three modes: modified median adaptive coding algorithm similar to the one used by JPEG-LS, block prediction, and midpoint prediction. Bit rate control algorithm tracks color flatness and buffer fullness to adjust the quantization bit depth for a pixel group in a way that minimizes compression artifacts while staying within the bitrate limits. Repeating recent pixels can be stored in 32-entry Indexed Color History buffer, which can be referenced directly by each group in a slice; this improves compression quality of computer-generated images. Alternatively, prediction residuals are computed and encoded with entropy coding algorithm based on delta size unit-variable length coding. Encoded pixel groups are then combined into slices of various height and width; common combinations include 100% or 25% picture width, and 8-, 32-, or 108-line height.
On 4 January 2017, HDMI 2.1 was announced which supports up to 10K resolution and uses DSC 1.2 for video that is higher than 8K resolution with 4:2:0 chroma subsampling.
eDP
Embedded DisplayPort is a display panel interface standard for portable and embedded devices. It defines the signaling interface between graphics cards and integrated displays. The various revisions of eDP are based on existing DisplayPort standards. However, version numbers between the two standards are not interchangeable. For instance, eDP version 1.4 is based on DisplayPort 1.2, while eDP version 1.4a is based on DisplayPort 1.3. In practice, embedded DisplayPort has displaced LVDS as the predominant panel interface in modern laptops.eDP 1.0 was adopted in December 2008. It included advanced power-saving features such as seamless refresh rate switching.
Version 1.1 was approved in October 2009 followed by version 1.1a in November 2009.
Version 1.2 was approved in May 2010 and includes DisplayPort 1.2 HBR2 data rates, 120Hz sequential color monitors, and a new display panel control protocol that works through the AUX channel.
Version 1.3 was published in February 2011; it includes a new optional Panel Self-Refresh feature developed to save system power and further extend battery life in portable PC systems. PSR mode allows the GPU to enter a power saving state in between frame updates by including framebuffer memory in the display panel controller.
Version 1.4 was released in February 2013; it reduces power consumption through partial-frame updates in PSR mode, regional backlight control, lower interface voltages, and additional link rates; the auxiliary channel supports multi-touch panel data to accommodate different form factors. Version 1.4a was published in February 2015; the underlying DisplayPort version was updated to 1.3 in order to support HBR3 data rates, Display Stream Compression 1.1, Segmented Panel Displays, and partial updates for Panel Self-Refresh. Version 1.4b was published in October 2015; its protocol refinements and clarifications are intended to enable adoption of eDP 1.4b in devices by mid-2016.
iDP
Internal DisplayPort 1.0 was approved in April 2010. The iDP standard defines an internal link between a digital TV system on a chip controller and the display panel's timing controller. It aims to replace currently used internal FPD-Link lanes with DisplayPort connection. iDP features unique physical interface and protocols, which are not directly compatible with DisplayPort and are not applicable to external connection, however they enable very high resolution and refresh rates while providing simplicity and extensibility. iDP features non-variable 2.7GHz clock and is nominally rated at 3.24Gbit/s data rate per lane, with up to sixteen lanes in a bank, resulting in six-fold decrease in wiring requirements over FPD-Link for a 1080p24 signal; other data rates are also possible. iDP was built with simplicity in mind and it doesn't have AUX channel, content protection, or multiple streams; however it does have frame sequential and line interleaved stereo 3D.PDMI
Portable Digital Media Interface is an interconnection between docking stations/display devices and portable media players, which includes 2-lane DisplayPort v1.1a connection. It has been ratified in February 2010 as ANSI/CEA-2017-A.wDP
Wireless DisplayPort enables DisplayPort 1.2 bandwidth and feature set for cable-free applications operating in 60GHz radio band; it was announced on November 2010 by WiGig Alliance and VESA as a cooperative effort.SlimPort
SlimPort, a brand of Analogix products, complies with Mobility DisplayPort, also known as MyDP, which is an industry standard for a mobile audio/video Interface, providing connectivity from mobile devices to external displays and HDTVs. SlimPort implements the transmission of video up to 4K-UltraHD and up to eight channels of audio over the micro-USB connector to an external converter accessory or display device. SlimPort products support seamless connectivity to DisplayPort, HDMI and VGA displays. The MyDP standard was released in June 2012, and the first product to use SlimPort was Google's Nexus 4 smartphone. Some LG smartphones in LG G series also adopted SlimPort.SlimPort is an alternative to Mobile High-Definition Link.
DisplayID
DisplayID is designed to replace the E-EDID standard. DisplayID features variable-length structures which encompass all existing EDID extensions as well as new extensions for 3D displays and embedded displays.The latest version 1.3 adds enhanced support for tiled display topologies; it allows better identification of multiple video streams, and reports bezel size and locations. As of December 2013, many current 4K displays use a tiled topology, but lack a standard way to report to the video source which tile is left and which is right. These early 4K displays, for manufacturing reasons, typically use two 1920×2160 panels laminated together and are currently generally treated as multiple-monitor setups. DisplayID 1.3 also allows 8K display discovery, and has applications in stereo 3D, where multiple video streams are used.
DockPort
DockPort, formerly known as Lightning Bolt, is an extension to DisplayPort to include USB 3.0 data as well as power for charging portable devices from attached external displays. Originally developed by AMD and Texas Instruments, it has been announced as a VESA specification in 2014.USB-C
On 22 September 2014, VESA published the DisplayPort Alternate Mode on USB Type-C Connector Standard, a specification on how to send DisplayPort signals over the newly released USB-C connector. One, two or all four of the differential pairs that USB uses for the SuperSpeed bus can be configured dynamically to be used for DisplayPort lanes. In the first two cases, the connector still can carry a full SuperSpeed signal; in the latter case, at least a non-SuperSpeed signal is available. The DisplayPort AUX channel is also supported over the two sideband signals over the same connection; furthermore, USB Power Delivery according to the newly expanded USB-PD 2.0 specification is possible at the same time. This makes the Type-C connector a strict superset of the use-cases envisioned for DockPort, SlimPort, Mini and Micro DisplayPort.VirtualLink
VirtualLink uses USB-C connectors and DisplayPort to transmit video signals.Products
Since its introduction in 2006, DisplayPort has gained popularity within the computer industry and is featured on many graphic cards, displays, and notebook computers. Dell was the first company to introduce a consumer product with a DisplayPort connector, the Dell UltraSharp 3008WFP, which was released in January 2008. Soon after, AMD and Nvidia released products to support the technology. AMD included support in the Radeon HD 3000 series of graphics cards, while Nvidia first introduced support in the GeForce 9 series starting with the GeForce 9600 GT.Later the same year, Apple introduced several products featuring a Mini DisplayPort. The new connector proprietary at the time eventually became part of the DisplayPort standard, however Apple reserves the right to void the license should the licensee "commence an action for patent infringement against Apple". In 2009, AMD followed suit with their Radeon HD 5000 Series of graphics cards, which featured the Mini DisplayPort on the Eyefinity versions in the series.
Nvidia launched NVS 810 with 8 Mini DisplayPort outputs on a single card on 4 November 2015.
Nvidia revealed the GeForce GTX 1080, the world's first graphics card with DisplayPort 1.4 support on 6 May 2016. AMD followed with the Radeon RX 480 to support DisplayPort 1.3/1.4 on 29 June 2016. The Radeon RX 400 Series will support DisplayPort 1.3 HBR and HDR10, dropping the DVI connector in the reference board design.
In February 2017, VESA and Qualcomm announced that DisplayPort Alt Mode video transport will be integrated into the Snapdragon 835 mobile chipset, which powers smartphones, VR/AR head-mounted displays, IP cameras, tablets and mobile PCs.
Support for DisplayPort Alternate Mode over USB-C
Participating companies
The following companies have participated in preparing the drafts of DisplayPort, eDP, iDP, DDM or DSC standards:- Agilent
- Altera
- AMD Graphics Product Group
- Analogix
- Apple
- Astrodesign
- BenQ
- Broadcom Corporation
- Chi Mei Optoelectronics
- Chrontel
- Dell
- Display Labs
- Foxconn Electronics
- FuturePlus Systems
- Genesis Microchip
- Gigabyte Technology
- Hardent
- Hewlett-Packard
- Hosiden
- Hirose Electric Group
- Intel
- intoPIX
- I-PEX
- Integrated Device Technology
- JAE Electronics
- Kawasaki Microelectronics
- Keysight Technologies
- Lenovo
- LG Display
- Luxtera
- Molex
- NEC
- NVIDIA
- NXP Semiconductors
- Xi3 Corporation
- Parade Technologies
- Realtek Semiconductor
- Samsung
- SMK
- STMicroelectronics
- SyntheSys Research Inc.
- Tektronix
- Texas Instruments
- TLi
- Tyco Electronics
- ViewSonic
- VTM
- Acer
- ASRock
- Biostar
- Chroma
- BlackBerry
- Circuit Assembly
- DataPro
- Eizo
- Fujitsu
- Hall Research Technologies
- ITE Tech.
- Matrox Graphics
- Micro-Star International
- MStar Semiconductor
- Novatek Microelectronics Corp.
- Palit Microsystems Ltd.
- Pioneer Corporation
- S3 Graphics
- Toshiba
- Philips
- Quantum Data
- Sparkle Computer
- Unigraf
- Xitrix