DisplayPort, or DP for short, is a digital display interface standard primarily used to connect a computer to a monitor. It was developed by the Video Electronics Standards Association (VESA) and was designed as a successor to VGA, DVI, and LVDS. DisplayPort offers several advantages over other display interface standards, including support for high-resolution displays, high refresh rates, and the ability to transmit audio and video over a single cable. DisplayPort is commonly used on computer monitors, graphics cards, and laptops, and is also used in some consumer electronics devices such as TVs and Blu-ray players. DisplayPort comes in different versions, with DisplayPort 2.1 being the most recent and offering the highest bandwidth and support for the latest display technologies.
A DisplayPort cable is a cable used to connect a computer or other device to a monitor or display device. It is specifically designed to transmit video and audio signals over a single cable using the DisplayPort standard. DisplayPort cables have a unique connector with 20 or more pins and are available in different lengths to accommodate different distances between the source device and the display device. DisplayPort cables are commonly used in computer systems and can support resolutions up to 8K, high refresh rates, and HDR content. They can also be used to daisy-chain multiple display devices, allowing for a multi-monitor setup without the need for multiple cables.
Transmission Speed
All DisplayPort cables support the same features. The primary difference between them is transmission speed. Resolution, color depth, number of monitors, refresh rate are all dependent on how much data the cable can transmit.
Updates to the DisplayPort standard typically include a boost in transmission speed (also referred to as bandwidth). To make it easier to find the cable you need, the VESA DisplayPort Task Group gives transmission speed a name.
Transmission Speed Max. Resolution High Bit Rate (HBR) 10.8 Gbps 4K/30 Hz High Bit Rate 2 (HBR2) 17.28 Gbps 4K @ 60 Hz High Bit Rate 3 (HBR3) 25.92 Gbps 4K @ 120 HzFor more detail, see DisplayPort Cables and DisplayPort 2.0 Monitor Configurations below.
Cable Length
Passive cables transmit signals. That's all they do. The longer the cable or the more data (higher resolution) you try to push through it, the more likely the signal will weaken and suffer from errors and interference.
The maximum length of a passive DisplayPort cable is at least 15 meters/33 feet. Depending on the quality of the cable and other factors, you may be able to transmit video and audio over greater distances.
Passive vs. Active Cables
If you need greater distance, you have two choices: a signal booster or an active cable. Both do essentially the same thing. They regenerate or increase the strength of the signal so it can be transmitted further. Depending on the resolution, active cables can easily reach 150-ft or more.
What is Display Stream Compression (DSC)?
High resolutions of 8K and beyond, greater color depths and increasing frame rates push the limits of video cables, even high bandwidth cables like DisplayPort. The only way to transmit more bits is to add more lanes to the cable or compress the signal. Display Stream Compression (DSC) is a new standard first introduced in DisplayPort 1.4 that enables visually lossless compression of 2:1 or 3:1. This "light compression" allows video to be encoded and decoded in real time with very low latency, making it ideal for high performance applications like gaming. Compared to video transmission without compression, DSC saves power and can allows for resolutions up to 16K (15360 x 8460). However, for the best image quality, it is best to avoid compression of any kind.
How do I check my DisplayPort version?
Graphics cards and port drivers do not usually indicate the version of DisplayPort they support but they will show maximum resolution and refresh rate (e.g. 4096 x 2304 @ 60 Hz). Identify the processor used by your computer, then refer to the graphics specifications on the manufacturer's website.
How do I daisy chain multiple monitors?
Multi-Stream Transport (MST) allows multiple displays to be driven by a single DP port. For more on the MST feature, see DisplayPort Multi-Stream Transport (MST) Explained.
What is Dual Mode DisplayPort?
Devices that support DisplayPort Dual-Mode will detect when an HDMI and DVI Single-Link monitors is connected and will send HDMI/DVI signals instead of DisplayPort. It is an optional feature that some device manufacturers implement but it is not required. How do you know if your laptop or dock supports DisplayPort Dual-Mode? The port is sometimes labeled with the DP++ logo but not always. Refer to the documentation that came with your device.
DisplayPort vs HDMI. What's the difference?
DisplayPort and HDMI are often compared because they have many of the same features. Aside from the fact that DP and HDMI use different connectors, DisplayPort has more of a computer focus whereas HDMI has become the de facto standard for connecting televisions and consumer AV products. By virtue of its higher bandwidth, DisplayPort supports higher display resolutions and refresh rates, making it a popular choice for gamers and professional video editors.
Does DisplayPort Support Audio?
Yes, DisplayPort can carry multi-channel digital audio and video signals simultaneously although it isn't always implemented by device manufacturers. If DP audio is supported by your PC graphics card or laptop, you will be able to stream audio to speakers built into your monitor or connect speakers to your monitor instead of your computer.
With each update of the DisplayPort standard, more bandwidth is required to support higher video resolutions, refresh rates and color depths. The effective data rate of DP 1.3 and 1.4 is sufficient to support a 4K, 24-bit color monitor at a refresh rate of up to 120 Hz, but it is not able to support the new generation of higher resolution 6K and 8K displays without resorting to compression.
DisplayPort Specification Year Typical Monitor Resolution Max. Data Rate (4 lanes)* Bit Rate Class 1.0 2006 1440p @ 60 Hz 5.18/8.64 Gbps RBR/HBR 1.1 2007 1440p @ 60 Hz 8.64 Gbps HBR 1.2 2009 4K @ 60 Hz 17.28 Gbps HBR2 1.3 2014 4K @ 120 HzDisplayPort 1.0 (2006)
DisplayPort 1.1 (2007)
DisplayPort 1.2 (2009)
DisplayPort 1.3 (2015)
DisplayPort 1.4 (2016)
DisplayPort 1.4a (2018)
DisplayPort 2.0 (2019)
In the latest DisplayPort specification, DP 2.0, you will see a maximum bandwidth of 80 Gbps and an effective bandwidth of 77.4 Gbps. What is the difference between the two?
DP 2.0 is built on the Thunderbolt 3 standard, which provides four 20 Gbps lanes for data transmission. While Thunderbolt utilizes two lanes (2 x 20 Gbps) in each direction, video transmission is outbound only so DisplayPort can devote all four lanes (a total of 80 Gbps) to video.
Raw video signals are transmitted with additional encoding that allows them to be reconstituted by the receiving device. Under the DP 1.x standards, a video signal was transmitted using the relatively inefficient 8b/10b encoding scheme (an 8-bit payload plus 2 encoding bits translates to a 25% overhead). DP 2.0 employs 128b/132b encoding and requires only 3.125% overhead (4 encoding bits for every 128 bits of video).
DP 2.0's effective bandwidth is calculated as follows:
Maximum Bandwidth: 4 lanes x 20 Gbps per lane = 80 Gbps
Effective Bandwidth: 80 Gbps minus 3.125% encoding overhead = 77.4 Gbps
What is a Color Space?
A color space is a defined range of colors that can be represented in an image. The two primary color spaces used to represent digital video are RGB and YCbCr. Two important characteristics of a color space are Color Depth and Gamut.
The initial HDMI specification provided support for 24-bit Color Depth (8-bits per color x 3 colors RGB). HDMI 1.3 introduced Deep Color, which added support for 30-bit, 36-bit and 48-bit color depths. It's worth keeping in mind that the human eye can only distinguish around 10 million different color, so 24-bit color is adequate for most situations.
Color Depths
Color Depth Bits per Color Also Known As Gamut HDMI Specification 24-Bit Color 8 True Color 16.7 million 1.0 30-Bit Color 10 Deep Color 1.073 billion 1.3 36-Bit Color 12 68.71 colors 48-Bit Color 16 281.5 trillionWhat is Chroma Subsampling?
Chroma subsampling is a form of video data compression. It reduces the amount of color data in a video signal in such a way that there is little or no visible impact on image quality.
Each pixel in a video image includes information on brightness (luma) and color (chroma). Since human eyes are more sensitive to differences in brightness than color, chroma subsampling reduces the amount of data transmitted by allowing pixels to share color data with adjacent pixels.
Chroma Subsampling is represented as three digits. The first number is the number of pixels in each row of the sample. The second number indicates the number of pixels in the TOP row that have color information. The third number indicates the number of pixels in the BOTTOM row that have color information.
DisplayPort 2.0 Monitor Configurations
With the greater bandwidth of DP 2.0, it is possible to connect two 4K monitors running at 144 Hz using a single cable and no compression. This should be good news for gamers and virtual reality (VR) enthusiasts, who look for ultra-high resolutions and refresh rates.
The tables below illustrate the versatility of the latest DP standard.
All DisplayPort cables have the same capabilities with the exception of transmission speed.
Four transmission modes are supported by DisplayPort 1.x cables: RBR, HBR, HBR2 and HBR3.
DisplayPort 2.0 introduced a fifth transmission mode, Ultra High Bit Rate (UHBR), which supports three new data rates per lane: 10 Gbps, 13.5 Gbps, and 20 Gbps. The maximum total bandwidth on a standard 4 lane connection is 4 x 20 Gbps or 80.00 Gbps.
8K DisplayPort to DisplayPort Cable
When a DisplayPort connection is made, the transmission mode is determined through a process called Link Training. This process determines the maximum speed of the connection. If the DisplayPort cable is not capable of maintaining a stable connection at a particular speed, the connected devices will "fallback" to a lower speed. The connected devices can agree on a new higher or lower speed at any time if signal errors are detected.
DisplayPort connectors come in two sizes: Standard DisplayPort and Mini DisplayPort (mDP). While these connectors differ in shape, they both have 20-pins and support the same features.
The Standard DP connector is typically used by PCs, laptop and displays. The smaller mDP connector was originally developed by Apple in 2008 and merged into the DisplayPort 1.2 specification in 2010.
mDP was also used as the connector for the Thunderbolt interface until it switched to the USB-C connector in Thunderbolt 3.
Both DP connectors use a friction lock. An optional latching mechanism is available on the larger version.
DisplayPort keystone jacks are also available with optional panel mount brackets. These can be used with standard faceplates in a variety of settings, including conference room podiums, classrooms and retail kiosks.
Some Standard DisplayPort connectors have a latching mechanism that prevents it from being accidentally disconnected. All DisplayPort receptacles have slots for the latches to lock into but the latches on the connector itself are optional.
In Alt Mode, some of the pins in a USB-C connector are used to transmit other protocols. This allows the widely adopted USB-C port/connector to be used for more than just data or power. To date, there are four Alternate Modes: DisplayPort, Mobile High-Definition Link (MHL), Thunderbolt and HDMI.
The latest version, DisplayPort Alt Mode 2.0, can transmit uncompressed 8K (7680 × 4320) video at 60 Hz or 16K (15360 x 8640) 60 Hz when using Display Stream Compression (DSC). Check the specs of your PC graphics card or laptop to see which version of DisplayPort is supported.
Is a USB4 port capable of transmitting a DisplayPort signal?
USB4 can transmit a DP 2.0 signal using Alt-Mode or USB4 protocol tunneling. When devices talk to one another, they do so using a protocol. If both devices can understand the same protocol, a connection can be established. Conceptually, Protocol Tunneling creates a "pipe" with one protocol and uses it to send data in another protocol. USB4 Protocol Tunneling creates a USB-C tunnel through which DisplayPort data can be sent. USB4 Protocol Tunneling is similar to Alt Mode but doesn't require a DP or PCIe controller.
According to VESA, the maximum length of a DisplayPort cable is 15 meters (49 feet) but distances of over 15 m are possible depending on resolution. A 15 m cable like Eaton's P580-050 can transmit a DP signal at 1080p. A good practical approach is to test transmission over the required distance with a good quality cable. If you see problems in the strength of the signal (e.g. sparkles or other artifacts), add a signal booster like Eaton's B121-000.
When transmission distance requirements exceed the limits of passive and active cables, it's time to consider the various forms of signal extension.
DisplayPort over CATx – A DP over CATx extender will convert the DisplayPort signal into a proprietary form that can be transmitted over the category cable and reconverted at the other end with no loss of signal strength or fidelity. Using this approach, a DisplayPort signal can be transmitted about three times further than an active DisplayPort cable–approximately 100 meters (328 ft.). Shielded (STP) Cat6 cable is recommended for its ability to reduce EMI interference from power lines and crosstalk within the cable.
DisplayPort over Fiber (Active Optical Cable) – The connectors on fiber DisplayPort convert conventional electrical inputs to pulses of light that are transmitted at high speed through optical fiber, then converted back to electricity on the receiving end. Since signal transmission is optical, it isn't subject to EMI/RFI line noise. Fiber DisplayPort is subject to the same 100 meter/328-foot limitation as copper Ethernet cable.
Wireless DisplayPort Extenders – A hardwired extender uses an Ethernet or Active Optical Cable to pass data between a transmitter and receiver. A wireless extender sends the DisplayPort signal using one of the WiFi protocols (e.g. 802.11ac or 802.11n). Wireless is generally slower than hardwire so make sure the video resolution and frequency is sufficient for your needs. For example, Eaton's B126-1D1-WHD1 can extend a 4K/30 Hz signal up to 98-ft.
For more on DisplayPort Video Extenders and how they work, see our Video Extenders Technology page.
Switches and splitters are often confused and for good reason. They perform similar functions. A switch takes multiple inputs and lets you choose which one to display on your TV or computer monitor. A splitter does exactly the opposite. It takes a single video signal and replicates it to multiple displays.
DisplayPort Splitters
A DisplayPort splitter takes one DisplayPort video signal and sends it to multiple displays. Each display will show the same image. Splitters are often classified according to their inputs and outputs. For example, a 2-port splitter might be referred to as "1x2" because it has one input and two outputs.
When choosing a splitter, make sure the output is at the resolution and frequency you want. A video splitter may also perform protocol conversion, for example, converting DisplayPort to HDMI.
DisplayPort Switches
A DisplayPort switch, also called a presentation switcher, outputs audio and video from multiple sources but only one at a time. For example, a boardroom presentation might include Powerpoint slides and video from a streaming service like YouTube or Vimeo.
A matrix switch has multiple inputs AND outputs. For example, a 9x2 matrix switch has 9 inputs and 2 outputs.
Another variation on the many-to-one theme is the Multiviewer, which consolidates a number of video inputs on a single monitor. Multiviewers are found in broadcast control rooms and video surveillance systems.
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