Video Displays Take a Great Leap Forward With DisplayPort 2.0
The latest DisplayPort connector standard will deliver the higher performance needed for immersive gaming, content streaming, and digital displays, as well as higher resolution and high dynamic range capability.
Home cinephiles, video gamers, event projectionists, and designers of videowalls and multiple chained-screen PC displays have reason to rejoice: The long-anticipated update to the DisplayPort audio/video standard has arrived. The new DisplayPort connector will have a transformative impact on screen-based technologies, bringing digital displays into compatibility with the latest generation of high-speed equipment. This important connectivity upgrade means screens will be able to keep up with the faster signals and massive amounts of data being sent their way. Movies, games, digital displays, and presentations will perform without lagging or distortion, in full resolution, depth, and richness, with maximum color complexity: 24-bit per pixel transmission currently supports 26.7 million colors, while the new 30-bit per pixel rate will support over a billion colors.
The changes aren’t seismic in terms of form factor; the DisplayPort 2.0 connector will have the same physical housing as the current DisplayPort 1.3 connector. But that’s where the similarity ends. Within the connector, DisplayPort 2.0 features four Thunderbolt 3 links inside the cable, enabling it to triple the bandwidth of the standard to 77.37Gb/s. The new standard will support one 16K signal at 60Hz, two 8K signals at 120Hz, or three 10K signals at 60Hz, all at 30 bits per pixel (bpp) 4:4:4 HDR with no compression. In tandem with new active optical cables that can support speeds of 10Gb/s, this advancement of connector technology will impact screens and monitors on laptops, PCs, televisions, gaming systems, and commercial screen applications. Augmented and virtual reality applications will take a great leap forward with DisplayPort 2.0.
DisplayPort products are offered by connector companies including TE Connectivity, Molex, FCI Amphenol, and JAE Electronics. We will begin to see Display 2.0 products in the coming months, and the new connector will be backwards compatible with earlier DisplayPort generations, as well as HDMI, VGA, and DVI. Adaptors will be available for legacy products. It can be combined with standards such as USB and Thunderbolt. DisplayPort is a Video Electronics Standards Association (VESA) standard. We talked to Bill Lempesis, Executive Director, VESA, to find out more.
In addition to computer monitors, what types of video displays are impacted by DisplayPort?
DisplayPort is applicable to any visual display application. DisplayPort source devices are able to drive not only DisplayPort displays but also HDMI displays and VGA projectors via DisplayPort protocol converters. In addition to serving as an external interface, DisplayPort is the basis for the Embedded DisplayPort (eDP) interface used for the majority of notebook PCs and higher-end tablets. eDP is used in automobiles for higher-resolution displays. DisplayPort can serve as the video output from a USB Type-C connector in the form of DisplayPort Alt Mode.
Will DisplayPort 2.0 impact primarily high-resolution, high-end products such as gaming computers, or are there widespread implications for video?
The high display transport data bandwidth of DisplayPort 2.0, known as ultra-high bit rates (UHBR), will benefit high-end products such as gaming computers/displays. It will also benefit multi-function docking stations and head mount displays for VR/AR. DisplayPort 2.0 introduces three new data rates: 10Gb/s per lane (UHBR10), 13.5Gb/s per lane (UHBR13.5), and 20Gb/s per lane (UHBR20). Using all four lanes, DisplayPort 2.0 provides a maximum link bandwidth of 80Gb/s, or a maximum payload of 77.37 Gb/s — up to a three-fold increase compared to the previous version of DisplayPort.
However, even on more standard resolution displays, such as 1080p, DisplayPort 2.0 is designed to save system power (using Panel Replay feature, for example) and enhance the ability to use a single USB Type-C connector for multiple monitors and high-speed USB data, concurrently.
Will older versions of DisplayPort still be in use in new products or does the industry move fully forward to 2.0?
DisplayPort 2.0 is fully backward compatible with the previous versions of the DisplayPort standard. Therefore, devices built for previous versions of DisplayPort and those built for DisplayPort 2.0 interoperate. While some companies may continue to implement a subset of the features or performance levels of DisplayPort 2.0 covered in the previous version of DisplayPort standards, we anticipate that most device manufacturers that are developing new products will begin incorporating new features and performance levels of DisplayPort 2.0, such as higher resolutions at higher refresh rates, improved support for multiple display configurations and improved power efficiency.
How does this impact connector choices for product designers?
UHBR rates are supported over native DisplayPort connectors and USB Type-C connectors. UHBR10 is supported over existing DisplayPort cables that have been certified for DP8K and existing USB Type-C cables capable of supporting USB3.x SuperSpeed, both of which are passive cables with the length of at least two meters. VESA’s Display Stream Compression (DSC) standard for DisplayPort devices capable of supporting UHBR rates further capitalizes on the utility of DisplayPort 2.0 connections. Higher bit rate modes (UHBR13.5 and UHBR20) are initially limited to tethered cable devices, such as laptop docks or AR/VR headsets, but future advances in cabling technology may support these higher modes for a wider range of applications over detachable cables.
What unique advantages do native DisplayPort connectors and USB Type-C connectors offer with regard to the new specification?
A device with a USB Type-C connector is required to provide for at least 4.5W of power on USB Type-C VBUS pins. Graphics accelerator add-in cards that have multiple DisplayPort output ports use native DisplayPort connectors in order to minimize the power requirement. USB-C connectors are well suited for multi-function docking stations and head-mount displays, as they come with USB3.x SuperSpeed data capabilities and power charging capabilities. The full-size standard DisplayPort connector also includes a latch option, which is often desirable for commercial and professional applications, such as digital signage.
How does the new specification impact cable decisions?
The higher link rates available in DisplayPort 2.0 will put more demand on cable performance. DisplayPort 2.0 will also increase the need for active cables, like what is seen today with Thunderbolt cables, for example. As displays start taking advantage of the higher performance enabled by DisplayPort 2.0, the demand for active cables will likely increase.
Does this specification fully address the demands 5G will impose?
5G will enhance the streaming capability of mobile devices. DisplayPort 2.0 helps a 5G-capable mobile device drive displays that are high resolution, high-frame-rate, and HDR-capable.
What challenges will the next update (3.0?) need to address?
Since the first version of DisplayPort was released in 2006, VESA has continuously evolved the standard over the years, anticipating the future needs of the marketplace. Newer versions of DisplayPort have been published to support not only higher resolutions, but also new video features and capabilities, such as video compression with forward error correction, multiple display streaming, and HDR. Future versions of DisplayPort will continue on this path, addressing further scalability in driving displays.
What else should video design engineers know about this specification?
So far, VESA has only completed cable requirements for link rates to 10Gb/s per lane. For the higher rates of 13.5 and 20Gb/s per lane, VESA is currently evaluating proposals for improved electrical parameters for both connectors and cables. It would be valuable for VESA to get more involvement and participation from the connector and cable vendors as we develop the draft and final cable specifications.