Exhibition

DisplayPort From Wikipedia - Specifications

Specifications[edit]

Main specifications[edit]

 DisplayPort Version
1.0–1.1a1.2–1.2a1.31.4–1.4a2.0
Release DateMay 2006 (1.0)[34]
Mar 2007 (1.1)[35]
Jan 2008 (1.1a)[9]
Jan 2010 (1.2)[12]
May 2012 (1.2a)[35]
Sep 2014[20]March 2016 (1.4)[23]
April 2018 (1.4a)[27]
June 2019[33]
Main Link
Transmission Modes:
RBR (1.62 Gbit/s per lane)Yes[36](§1.6.1)YesYesYesYes
HBR (2.70 Gbit/s per lane)Yes[36](§1.6.1)YesYesYesYes
HBR2 (5.40 Gbit/s per lane)NoYes[37](§2.1.1)YesYesYes
HBR3 (8.10 Gbit/s per lane)NoNoYes[20]YesYes
UHBR 10 (10.0 Gbit/s per lane)NoNoNoNoYes
UHBR 13.5 (13.5 Gbit/s per lane)NoNoNoNoYes
UHBR 20 (20.0 Gbit/s per lane)NoNoNoNoYes
Number of Lanes(§1.7.1)[9] 44444
Maximum Total Bandwidth[a]10.80 Gbit/s21.60 Gbit/s32.40 Gbit/s32.40 Gbit/s80.00 Gbit/s
Maximum Total Data Rate[b]8.64 Gbit/s
17.28 Gbit/s25.92 Gbit/s25.92 Gbit/s77.37 Gbit/s
Encoding Scheme[c](§1.7.1)[9] 8b/10b8b/10b8b/10b8b/10b128b/132b
Compression (Optional)---DSC 1.2 (DP 1.4)
DSC 1.2a (DP 1.4a)
DSC 1.2a
Auxiliary Channel
Maximum Bandwidth(Fig. 3-3)[9] 2 Mbit/s(§3.4)[37] 720 Mbit/s720 Mbit/s720 Mbit/s?
Maximum Data Rate(§3.4)[9] 1 Mbit/s(§3.4)[37] 576 Mbit/s576 Mbit/s576 Mbit/s?
Encoding Scheme(§1.7.2)[9] Manchester II(§3.4)[37] 8b/10b8b/10b8b/10b?
Color Format Support
RGBYes[36](§1.6.1)YesYesYesYes
Y′CBCR 4:4:4Yes[36](§1.6.1)YesYesYesYes
Y′CBCR 4:2:2Yes[36](§1.6.1)YesYesYesYes
Y′CBCR 4:2:0NoNoYesYesYes
Y-Only (Monochrome)NoYes[37](§2.2.4.3)YesYesYes
Color Depth Support
6 bpc (18 bit/px)Yes[36](§1.6.1)YesYesYesYes
8 bpc (24 bit/px)Yes[36](§1.6.1)YesYesYesYes
10 bpc (30 bit/px)Yes[36](§1.6.1)YesYesYesYes
12 bpc (36 bit/px)Yes[36](§1.6.1)YesYesYesYes
16 bpc (48 bit/px)Yes[36](§1.6.1)YesYesYesYes
Color Space Support
ITU-R BT.601Yes[9](§2.2.4)YesYesYesYes
ITU-R BT.709Yes[9](§2.2.4)YesYesYesYes
sRGBNo[d]Yes[37](§2.2.4.3)YesYesYes
scRGBNoYes[37](§2.2.4.3)YesYesYes
xvYCCNoYes[37](§2.2.4.3)YesYesYes
Adobe RGB (1998)NoYes[37](§2.2.4.3)YesYesYes
DCI-P3NoYes[37](§2.2.4.3)YesYesYes
Simplified Color ProfileNoYes[37](§2.2.4.3)YesYesYes
ITU-R BT.2020NoNoYes[38](p4)YesYes
Audio Specifications
Max. Sample Rate(§1.2.5)[9] 192 kHz(§2.2.5.3)[37] 768 kHz768 kHz[23] 1536 kHz?
Max. Sample Size(§1.2.5)[9] 24 bits24 bits24 bits24 bits?
Maximum Audio Channels(§1.2.5)[9] 88832?
 1.0–1.1a1.2–1.2a1.31.4–1.4a2.0
DisplayPort Version
  1. ^ Total bandwidth (the number of binary digits transmitted per second) is equal to the bandwidth per lane of the highest supported transmission mode multiplied by the number of lanes.

  2. ^ While the total bandwidth represents the number of physical bits transmitted across the interface, not all of the bits represent video data. Some of the transmitted bits are used for encoding purposes, so the rate at which video data can be transmitted across the DisplayPort interface is only a portion of the total bandwidth.

  3. ^ The 8b/10b encoding scheme uses 10 bits of bandwidth to send 8 bits of data, so only 80% of the bandwidth is available for data throughput. The extra 2 bits are used for DC balancing (ensuring a roughly equal number of 1s and 0s). They consume bandwidth, but do not represent any data.

  4. ^ In DisplayPort 1.0–1.1a, RGB images are simply sent without any specific colorimetry information

Main link[edit]

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.[39](p4)


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.[9](§1.7.1) 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".[9](§2.2.1.4)

In DisplayPort versions 1.0–1.4a, 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 (ensuring a roughly equal number of 1s and 0s). 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 (i.e. the rate at which groups of 10 bits are transmitted, 8 of which represent data). The following transmission modes are defined in version 1.0–1.4a:

DisplayPort 2.0 uses 128b/132b encoding; each group of 132 transmitted bits represents 128 bits of data. This scheme has an efficiency of 96.96%. In addition, forward error correction (FEC) consumes a small amount of the link bandwidth, resulting in an overall efficiency of ≈96.7%.[40] The following transmission modes are added in DP 2.0:

The total bandwidth of the main link in a standard 4-lane connection is the aggregate of all lanes:

The transmission mode used by the DisplayPort main link is negotiated by the source and sink device when a connection is made, through a process called Link Training. This process determines the maximum possible speed of the connection. If the quality of the DisplayPort cable is insufficient to reliably handle HBR2 speeds for example, the DisplayPort devices will detect this and switch down to a lower mode to maintain a stable connection.[9](§2.1.1) The link can be re-negotiated at any time if a loss of synchronization is detected.[9](§1.7.3)

Audio data is transmitted across the main link during the video blanking intervals (short pauses between each line and frame of video data).[9](§2.2.5.3)

Auxiliary channel[edit]

The DisplayPort AUX channel is a half-duplex bidirectional data channel used for miscellaneous additional data beyond video and audio (such as I2C or CEC commands)[9](§2.4) at the device manufacturer's discretion. AUX signals are transmitted across a dedicated set of twisted-pair wires. DisplayPort 1.0 specified Manchester encoding with a 2 Mbaud signal rate (1 Mbit/s data rate).[9](§3.4) DisplayPort 1.2 introduced a second transmission mode called FAUX (Fast AUX), which operates at 720 Mbaud with 8b/10b encoding (576 Mbit/s data rate).[37](§3.4) This can be used to implement additional transport protocols such as USB 2.0 (480 Mbit/s) without the need for an additional cable, but has seen little practical use as of 2018.

Cables and connectors[edit]

Cables[edit]

Compatibility and feature support[edit]

All DisplayPort cables are compatible with all DisplayPort devices, regardless of the version of each device or the cable certification level.[41]

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 (RBR, HBR, HBR2, and HBR3) 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 "DisplayPort 1.2 cables" for example, this notation is not permitted by VESA.[41] The use of version numbers with cables can seem to imply that a DisplayPort 1.4 display requires a "DisplayPort 1.4 cable", or that features introduced in DP 1.4 such as HDR or DSC will not function with older "DP 1.2 cables", when in reality neither of these are true. DisplayPort cables are classified only by their bandwidth certification level (RBR, HBR, HBR2, HBR3), if they have been certified at all.

Cable bandwidth and certifications[edit]

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:

DisplayPort Cable Certifications
Transmission ModeTransmission
Bit Rate
DP Version
Introduced In
Minimum Cable
Certification Required
RBR (Reduced Bit Rate)6.48 Gbit/s
1.0
RBR DisplayPort Cable
HBR (High Bit Rate)10.80 Gbit/sStandard DisplayPort Cable
HBR2 (High Bit Rate 2)21.60 Gbit/s
1.2
HBR3 (High Bit Rate 3)32.40 Gbit/s
1.3
DP8K DisplayPort Cable
UHBR 10 (Ultra High Bit Rate 10)40.00 Gbit/s
2.0

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 DisplayPort 1.1—would be able to handle the 21.6 Gbit/s bandwidth of HBR2 that was introduced with the DisplayPort 1.2 standard.[41] The DisplayPort 1.2 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 (CTS) and not the DisplayPort standard itself.[37](§5.7.1, §4.1)

The DP8K certification was announced by VESA in January 2018, and certifies cables for proper operation at HBR3 speeds (8.1 Gbit/s per lane, 32.4 Gbit/s total).[42]

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.[40]

It should also be noted that the use of Display Stream Compression (DSC), introduced in DisplayPort 1.4, greatly reduces the bandwidth requirements for the cable. Formats which would normally be beyond the limits of DisplayPort 1.4, such as 4K (3840 × 2160) at 144 Hz 8 bpc RGB/4:4:4 (31.4 Gbit/s data rate when uncompressed), 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 "DP 1.4 cable" (an HBR3-rated cable) to function. HBR3 cables are only required for applications which exceed HBR2-level bandwidth, not simply any application involving DisplayPort 1.4. If DSC is used to reduce the bandwidth requirements to HBR2 levels, then an HBR2-rated cable will be sufficient.

Cable length[edit]

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 (21.6 Gbit/s), and all cables of any length must support RBR speeds (6.48 Gbit/s).[37](§5.7.1, §4.1) Cables greater 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[edit]

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[edit]

The standard DisplayPort connector (now referred to as a "full-size" connector to distinguish it from the mini connector)[37](§4.1.1) was the sole connector type introduced in DisplayPort 1.0. It is a 20-pin single-orientation connector with a friction lock and an optional mechanical latch. The standard DisplayPort receptacle has dimensions of 16.10 mm (width) × 4.76 mm (height) × 8.88 mm (depth).[9](§4.2.1.7, p201)

The standard DisplayPort connector pin allocation is as follows:[9](§4.2.1)

Mini DisplayPort connector[edit]

The Mini DisplayPort connector was developed by Apple for use in their computer products. It was first announced in October 2008 for use in the new MacBook Pro, MacBook Air, and Cinema Display. In 2009, VESA adopted it as an official standard, and in 2010 the specification was merged into the main DisplayPort standard with the release of DisplayPort 1.2. Apple freely licenses the specification to VESA.

The Mini DisplayPort (mDP) 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 7.50 mm (width) × 4.60 mm (height) × 4.99 mm (depth).[43](§2.1.3.6, pp27–31) The mDP pin assignments are the same as the full-size DisplayPort connector.[43](§2.1.3)

DP_PWR Pin[edit]

Pin 20 on the DisplayPort connector, called DP_PWR, provides 3.3 V (±10%) DC power at up to 500 mA (minimum power delivery of 1.5 W).[9](§3.2) 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 (especially with a ±10% tolerance).[44] For this reason, the DisplayPort 1.1 and later standards specify that passive DisplayPort-to-DisplayPort cables must leave pin 20 unconnected.[9](§3.2.2)

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:

Recently VESA has experienced quite a few complaints regarding troublesome DisplayPort operation that ended up being caused by improperly made DisplayPort cables. These "bad" DisplayPort cables are generally limited to non-DisplayPort certified cables, or off-brand cables. To further investigate this trend in the DisplayPort cable market, VESA purchased a number of non-certified, off-brand cables and found that an alarmingly high number of these were configured improperly and would likely not support all system configurations. None of these cables would have passed the DisplayPort certification test, moreover some of these cables could potentially damage a PC, laptop, or monitor.

The stipulation that the DP_PWR wire be omitted from standard DisplayPort cables was not present in the DisplayPort 1.0 standard. However, DisplayPort products (and cables) did not begin to appear on the market until 2008, long after version 1.0 had been replaced by version 1.1. The DisplayPort 1.0 standard was never implemented in commercial products.[45]

Resolution and refresh frequency limits[edit]

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 (RBR, HBR, HBR2, HBR3, UHBR 10, UHBR 13.5, or UHBR 20). These transmission modes were introduced to the DisplayPort standard as follows:

However, transmission mode support is not necessarily dictated by a device's claimed "DisplayPort version number". For example, older versions of the DisplayPort Marketing Guidelines allowed a device to be labeled as "DisplayPort 1.2" if it supported the MST feature, even if it didn't support the HBR2 transmission mode.[46](p9) Newer versions of the guidelines have removed this clause, and currently (as of the June 2018 revision) there are no guidelines on the usage of DisplayPort version numbers in products.[47] DisplayPort "version numbers" are therefore not a reliable indication of what transmission speeds a device can support.

In addition, individual devices may have their own arbitrary limitations beyond transmission speed. For example, NVIDIA Kepler GK104 GPUs (such as the GeForce GTX 680 and 770) support "DisplayPort 1.2" with the HBR2 transmission mode, but are limited to 540 Mpx/s, only 34 of the maximum possible with HBR2.[48] 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. (See: Cables and connectors)

Refresh frequency limits for standard video[edit]

Color depth of 8 bpc (24 bit/px or 16.7 million colors) 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.


Limits for uncompressed RGB / Y′CBCR 4:4:4 video only
  1. ^ Only a portion of DisplayPort's bandwidth is used for carrying video data. DisplayPort versions 1.0–1.4a use 8b/10b encoding, which means that 80% of the bits transmitted across the link represent data, and the other 20% are used for encoding purposes. The maximum bandwidth of RBR, HBR, HBR2, and HBR3 (6.48, 10.8, 21.6, and 32.4 Gbit/s) therefore transport video data at rates of 5.184, 8.64, 17.28, and 25.92 Gbit/s. DisplayPort version 2.0 uses 128b/132b encoding, and therefore the maximum bandwidths of UHBR 10, 13.5, and 20 (40, 54, and 80 Gbit/s) transport data at rates of 39.69, 52.22, and 77.37 Gbit/s.

  2. ^ These data rates are for uncompressed 8 bpc (24 bit/px) color depth with RGB or YCBCR 4:4:4 color format and CVT-R2 timing. Uncompressed data rate for RGB video in bits per second is calculated as bits per pixel × pixels per frame × frames per second. Pixels per frame includes blanking intervals as defined by CVT-R2.

  3. a b Although this format slightly exceeds the maximum data rate of this transmission mode with CVT-R2 timing, it is close enough to be achieved with non-standard timings


Limits including compression and chroma subsampling
  1. ^ Only a portion of DisplayPort's bandwidth is used for carrying video data. DisplayPort versions 1.0–1.4a use 8b/10b encoding, which means that 80% of the bits transmitted across the link represent data, and the other 20% are used for encoding purposes. The maximum bandwidth of RBR, HBR, HBR2, and HBR3 (6.48, 10.8, 21.6, and 32.4 Gbit/s) therefore transport video data at rates of 5.184, 8.64, 17.28, and 25.92 Gbit/s. DisplayPort version 2.0 uses 128b/132b encoding, and therefore the maximum bandwidths of UHBR 10, 13.5, and 20 (40, 54, and 80 Gbit/s) transport data at rates of 39.69, 52.22, and 77.37 Gbit/s.

  2. ^ These data rates are for uncompressed 8 bpc (24 bit/px) color depth with RGB or YCBCR 4:4:4 color format and CVT-R2 timing. Uncompressed data rate for RGB video in bits per second is calculated as bits per pixel × pixels per frame × frames per second. Pixels per frame includes blanking intervals as defined by CVT-R2.

  3. ^ This format can only be achieved with full RGB color if DSC (display stream compression) is used.

  4. ^ This format can only be achieved uncompressed if the YCBCR format with either 4:2:2 or 4:2:0 chroma subsampling (as noted) is used

  5. ^ This format can only be achieved if DSC is used together with either YCbCr 4:2:2 or 4:2:0 chroma subsampling (as noted)

  6. a b Although this format slightly exceeds the maximum data rate of this transmission mode with CVT-R2 timing, it is close enough to be achieved with non-standard timings

Refresh frequency limits for HDR video[edit]

Color depth of 10 bpc (30 bit/px or 1.07 billion colors) 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 8 bpc 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 (for example, on 4K 60 Hz HDR displays). 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.[49] As a result, DisplayPort "version numbers" should not be used as an indicator of HDR support.


Limits for uncompressed RGB / Y′CBCR 4:4:4 video only
  1. ^ Only a portion of DisplayPort's bandwidth is used for carrying video data. DisplayPort versions 1.0–1.4a use 8b/10b encoding, which means that 80% of the bits transmitted across the link represent data, and the other 20% are used for encoding purposes. The maximum bandwidth of RBR, HBR, HBR2, and HBR3 (6.48, 10.8, 21.6, and 32.4 Gbit/s) therefore transport video data at rates of 5.184, 8.64, 17.28, and 25.92 Gbit/s. DisplayPort version 2.0 uses 128b/132b encoding, and therefore the maximum bandwidths of UHBR 10, 13.5, and 20 (40, 54, and 80 Gbit/s) transport data at rates of 39.69, 52.22, and 77.37 Gbit/s.

  2. ^ These data rates are for uncompressed 10 bpc (30 bit/px) color depth with RGB or YCBCR 4:4:4 color format and CVT-R2 timing. Uncompressed data rate for RGB video in bits per second is calculated as bits per pixel × pixels per frame × frames per second. Pixels per frame includes blanking intervals as defined by CVT-R2.

  3. a b c d e Although this format slightly exceeds the maximum data rate of this transmission mode with CVT-R2 timing, it is close enough to be achieved with non-standard timings


Limits including compression and chroma subsampling
  1. ^ Only a portion of DisplayPort's bandwidth is used for carrying video data. DisplayPort versions 1.0–1.4a use 8b/10b encoding, which means that 80% of the bits transmitted across the link represent data, and the other 20% are used for encoding purposes. The maximum bandwidth of RBR, HBR, HBR2, and HBR3 (6.48, 10.8, 21.6, and 32.4 Gbit/s) therefore transport video data at rates of 5.184, 8.64, 17.28, and 25.92 Gbit/s. DisplayPort version 2.0 uses 128b/132b encoding, and therefore the maximum bandwidths of UHBR 10, 13.5, and 20 (40, 54, and 80 Gbit/s) transport data at rates of 39.69, 52.22, and 77.37 Gbit/s.

  2. ^ These data rates are for uncompressed 10 bpc (30 bit/px) color depth with RGB or YCBCR 4:4:4 color format and CVT-R2 timing. Uncompressed data rate for RGB video in bits per second is calculated as bits per pixel × pixels per frame × frames per second. Pixels per frame includes blanking intervals as defined by CVT-R2.

  3. ^ This format can only be achieved with full RGB color if DSC (display stream compression) is used.

  4. ^ This format can only be achieved uncompressed if the YCBCR format with either 4:2:2 or 4:2:0 chroma subsampling (as noted) is used

  5. ^ This format can only be achieved if DSC is used together with either YCbCr 4:2:2 or 4:2:0 chroma subsampling (as noted)

  6. a b c d e Although this format slightly exceeds the maximum data rate of this transmission mode with CVT-R2 timing, it is close enough to be achieved with non-standard timings