Originally published 12 October 2022, last updated 11 January 2023
You’ve all heard of DisplayPort before, a common video interface featured on nearly all graphics cards and monitors nowadays. DisplayPort (herein shortened to “DP” in many places) is a digital display interface developed by a consortium of PC and chip manufacturers and standardized by the Video Electronics Standards Association (VESA). It is primarily used to connect a video source to a display device such as a computer monitor and as well as video, it can carry audio, USB, and other forms of data.
DisplayPort was designed to replace VGA, FPD-Link, and Digital Visual Interface (DVI) and is backward compatible with other interfaces, such as HDMI and DVI, through the use of either active or passive adapters. DisplayPort was originally developed as the next generation personal computer display interface and is now available on a wide range of tablets, notebooks, and desktop computers as well as monitors. It is now also becoming available on digital televisions, including some 4K TVs, as a display input.
This article will take you through the latest generation of DP that you will soon start to hear more about, and that is now, as of 17 October 2022, DisplayPort 2.1. We will refer to this as “DP 2.1” throughout now that this updated version has been announced. The initial DP 2.0 standard for which this article was originally written was published in June 2019, although actual consumer DP 2.0 devices in the monitor and display space have yet to appear. DP 2.1 supersedes the 2.0 generation. The standard “defines the new normative requirement and informative guideline for component and system design” as VESA put it. The new DisplayPort capabilities included in DisplayPort 2.0 / 2.1 have begun the cycle of hardware development that will result in such technology becoming available to consumers in a range of products over the next few years. More discussion on timescales later on.
DP 2.1 will update on the current DP 1.4 capabilities, but like other new versions in the past, DisplayPort 2.1 is backward compatible with earlier DisplayPort standards. You may already have heard about DP 2.0 / DP 2.1, and if not you are bound to see more of it in the not-to-distant future.
The common questions and considerations about DP 2.1 would include:
- Do consumers need to be worried about the certification or branding like they do with HDMI 2.1?
- Is there confusion around which features are and are not included?
- How will VESA certify products?
- What logos will be used?
- What about DP 2.1 cables?
- How will you tell what capabilities a display features?
All these questions and more will be answered in this article.
DisplayPort 2.1 Bandwidth and UHBR Explained
The key improvement and new capability with DP 2.1 is the increased bandwidth that it can support. Current DP 1.4 connections can support a maximum bandwidth of 32.40 Gbps with a 25.92 Gbps data rate. This has been surpassed in the last couple of years by the now fairly readily available HDMI 2.1 connection, delivering 48.0 Gbps total bandwidth, and a 42.0 Gbps data rate. We will explain encoding and data rates more in a moment. With DP 1.4 being more limited, for the latest high resolution and high refresh rate displays to work over DP at their full potential, manufacturers have however been able to make use of VESA’s Display Stream Compression (DSC) which provides a compression technique that is lossless visually and works very well.
DP 2.1 supports 3x the bandwidth of DP 1.4
up to 80 Gbps bandwidth = 77.37 Gbps data rate
With DP 2.1 the maximum bandwidth capability will be increased significantly to 3x that of DP 1.4, allowing for a total 80 Gbps bandwidth, and 77.37 Gbps data rate. So DP 2.1 devices will potentially be able to support significantly higher bandwidths than DP 1.4 devices, and surpass even the latest modern HDMI 2.1 connection. This allows for potentially higher resolutions and refresh rates in displays which is of course great news.
Ultra-High Bit Rate = UHBR
VESA refer to these new bandwidth capabilities as “Ultra-High Bit Rate” (UHBR), an advancement on High Bit Rate 3 (HBR3) from the current DP 1.4 standard. The DisplayPort main link is used for transmission of video and audio and this 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.
DisplayPort 1.4 had a maximum HBR3 of 4x 8.10 Gbps lanes, giving 32.40 Gbps total bandwidth, with a data rate of 25.92 Gbps. For the new DP 2.1 connections there are actually three tiers of UHBR available, which are associated with the bandwidth available from the device. These are shown below. The name for each UHBR tier relates to the bandwidth per lane as you can see:
|Transmission mode||DP revision||Bandwidth per lane (x4) Gbps||Total bandwidth Gbps||Total data rate Gbps|
Encoding Scheme Improvements
For the particularly technical of you we provide a bit more information about the encoding scheme which explains why there is a difference between the total bandwidth figures you see listed, and the available data rate. There have been some decent improvements in the encoding to allow DP 2.1 to make practical use of more of the bandwidth.
In older DP versions 1.0 to 1.4a, the data is encoded using ANSI 8b/10b encoding prior to transmission (also listed as 810 Mhz). 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. This is why the data rate of DP 1.4 is 25.92 Gbps, whereas the bandwidth total is 32.40 Gbps (=80% usage).
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:
- RBR (Reduced Bit Rate): 1.62 Gbit/s bandwidth per lane (162 MHz link symbol rate)
- HBR (High Bit Rate): 2.70 Gbit/s bandwidth per lane (270 MHz link symbol rate)
- HBR2 (High Bit Rate 2): 5.40 Gbit/s bandwidth per lane (540 MHz link symbol rate), introduced in DP 1.2
- HBR3 (High Bit Rate 3): 8.10 Gbit/s bandwidth per lane (810 MHz link symbol rate), introduced in DP 1.3, also used for DP 1.4
DisplayPort 2.1 on the other hand uses 128b/132b encoding; each group of 132 transmitted bits represents 128 bits of data. This scheme has a much higher 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%. This means that the transferrable data rate can be much closer to the bandwidth capacity of the connection. So for DP 2.1 you get up to 77.37 Gbps data rate out of 80Gbps total bandwidth (=96.7%). An updated version of our earlier table is included below to show the efficiency rate:
|Transmission mode||DP revision||Bandwidth per lane (x4) Gbps||Total bandwidth Gbps||Efficiency||Total data rate Gbps|
DisplayPort 2.1 Capabilities and Display Options
So the significant increase to bandwidth is a key part of DP 2.1, but what can this deliver to the end-user, and what else is available that’s new? As VESA explain on their website, the important features made possible by the latest DisplayPort 2.1 interface include:
- Higher refresh rates and high dynamic range (HDR) support at higher resolutions
- Improved support for multiple display configurations
- Improved user experience with augmented/virtual reality (AR/VR) displays, including support for 4K-and-beyond VR resolutions.
- Advantages of DP 2.1 are enjoyed across both the native DP connector as well as the USB Type-C connector
- Support for visually lossless Display Stream Compression (DSC) with Forward Error Correction (FEC), HDR metadata transport, and other advanced features
Some headline resolution and refresh rate examples made possible by DisplayPort 2.1 bandwidth even without needing to use DSC and with 10-bit colour depth/HDR:
- 8K 60Hz
- 4K 240Hz
- 1440p 480Hz and 500Hz
- Two 4K 120Hz displays
- Four 4K 60Hz displays
VESA provide some further example configurations made possible by DP 2.1 with and without DSC in use to whet your appetite:
- Support for 8K resolution (7680 x 4320) at 60Hz refresh rate with full 4:4:4 chroma and 10-bit colour depth for HDR
- Beyond 8K resolutions when using Display Stream Compression (DSC): Example Configurations:
- Single display resolutions
- One 16K (15360×8460) display @60Hz and 30 bpp (210-bit) 4:4:4 HDR (with DSC)
- One 10K (10240×4320) display @60Hz and 24 bpp (8-bit) 4:4:4 (no compression)
- Dual display resolutions
- Two 8K (7680×4320) displays @120Hz and 30 bpp (10-bit) 4:4:4 HDR (with DSC)
- Two 4K (3840×2160) displays @144Hz and 24 bpp (8-bit) 4:4:4 (no compression)
- Triple display resolutions
- Three 10K (10240×4320) displays @60Hz and 30 bpp (10-bit) 4:4:4 HDR (with DSC)
- Three 4K (3840×2160) displays @90Hz and 30 bpp (10-bit) 4:4:4 HDR (no compression)
- Single display resolutions
- When using only two lanes on the USB-C connector via DP Alt Mode to allow for simultaneous SuperSpeed USB data and video, DP 2.1 can enable such configurations as:
- Three 4K (3840×2160) displays @144Hz and 30 bpp (10-bit) 4:4:4 HDR (with DSC)
- Two 4Kx4K (4096×4096) displays (for AR/VR headsets) @120Hz and 30 bpp (10-bit) 4:4:4 HDR (with DSC)
- Three QHD (2560×1440) @120Hz and 24 bpp (8-bit) 4:4:4 (no compression)
- One 8K (7680×4320) display @30Hz and 30 bpp (10-bit) 4:4:4 HDR (no compression)
DisplayPort 1.2 and 1.4 Certification will Continue to be Used
Thankfully unlike the mess that the HDMI forum created with HDMI 2.1 where everything could end up being certified as “HDMI 2.1”, VESA will still be certifying devices under the older DisplayPort 1.4, and even DP 1.2, schemes where applicable or required. Not everything is going to be certified as DP 2.1, which would have left consumers to try and figure out which features are really included. If a device only has DP 1.2 or DP 1.4 capabilities, and perhaps only needs those capabilities to support it, then those schemes will continue to be available and certified against. This is definitely good news we think, as it means that when you see DP 2.1 listed, you know it should include that specific newer connection, and will support at least some of the features and capabilities associated with this new generation. However, as you read on, you will see it’s unfortunately not as simple as it perhaps should be…
To mandate that the entire supply chain must move as one to the latest spec would be disruptive VESA tell us, and also would be impractical from a cost perspective, as well as being unnecessary in many cases. For example, a 1080p 240Hz monitor will not require the extremely high bandwidths associated with Ultra-high Bit Rates (UHBRs), which are added to DP 2.1 and can simply be certified to existing DP 1.4 standards instead. Only devices that include some of the new capabilities from DP 2.1 will earn the DP 2.1 certification, otherwise they would simply be certified using the older versions.
What is Needed for DP 2.1 Certification?
Having spoken to VESA about the new scheme, we have confirmed that DP 2.1 devices must as a baseline have:
- Display Stream Compression (DSC), providing visually lossless compression and opening the door to significant improvements in resolutions and refresh rates. VESA has invested extensively in visual quality studies through York University to prove that DSC is truly visually lossless not only for SDR but for HDR content. DSC can reduce DisplayPort transport bandwidth in excess of 67% without visual artifacts, enabling higher refresh rates and resolutions, as well as multiple monitor support.
- The DisplayPort 2.1 update on 17 Oct 2022 also implies there is another capability that must be included with DP 2.1 which is Panel Relay. This can apparently reduce DisplayPort tunneling packet transport bandwidth in excess of 99% when Panel Replay operation is taking place.
Then, they tell us it must also have at least one of the following features:
- UHBR with 128/132b encoding which has only 3% overhead
- AdaptiveSync Secondary Data Packets which are needed to support the Adaptive-Sync protocol
- Link-Training Tunable PHY Repeaters (LTTPRs) which help maintain signal integrity for high-speed DisplayPort signal transmission from source to sink.
Unless a device can support at least one of these on top of DSC, it cannot be certified to the DP 2.1 specification.
Likely Confusion and Potential Abuse
There’s one aspect of these requirements we really don’t personally understand or like, and that’s the fact that apparently UHBR is going to be optional! We fail to see how this makes sense to anyone to be honest. The first thing people think of when they hear “DisplayPort 2.1” (or “DisplayPort 2.0” as it was before) is the increased bandwidth potential. It’s plastered all over VESA’s website here and here as the first “important feature” of the new standard. Every place in the media that talks about DP 2.1 is focused on the new bandwidth and for good reason, that’s really the big change here. At no point have VESA said “oh, hang on, UHBR speeds aren’t necessarily needed for a device to be DP 2.1”!
If, as VESA tell us, the UHBR aspect is basically optional, this means that in theory you could have a device certified as DP 2.1 when it doesn’t even include UHBR speeds of any sort! What if a manufacturer instead provided DSC like they have to as a baseline, and then added AdaptiveSync or LTTPRs, but didn’t bother with UHBR? That would still pass DP 2.1 criteria apparently, but you’d never actually get the new UHBR speeds. The device could still only support older HBR3 speeds from DP 1.4.
Maybe this won’t be too much of a problem, and maybe manufacturers will kindly list the UHBR speed for any device they promote as DP 2.1. But it does add a layer of complexity and confusion to the new scheme that we think is unnecessary. In our opinion, UHBR should be a baseline requirement. We don’t really mind if that is only the lowest UHBR10, or the higher UHBR13.5 or UHBR20, but one of these new speeds should be required for it to be considered DP 2.1 in our opinion and that speed should be whatever is required to support the resolution and refresh rate promoted without needing any compression measures (excluding DSC) that would impact the visual experience.
Let’s imagine a hypothetical and made up 4K display that offers a 200Hz refresh rate and is promoted as featuring DisplayPort 2.1 in the specs (no other details provided). In one case this could be a “proper” DP 2.1 connection which supports UHBR20 (80Gbps bandwidth) and can therefore run comfortably at 4K 200Hz, 10-bit colour depth and RGB (4:4:4) chroma, even without needing to use DSC. On the other hand the DP 2.1 may only support HBR3 speeds and instead what the manufacturer is not telling you is that to get 4K 200Hz you have to drop to 8-bit colour depth and 4:2:0 chroma to fit within the HBR3 data rate (this is without DSC). This is an extreme example and we would hope for transparency from display manufacturers when providing specs, but it is still an area that could lead to confusion or possibly to abuse.
VESA make the point that there is no need for manufacturers to have a higher price point because of the additional silicon needed to support UHBR, if the device simply does not need that. That’s true, but we believe that DP 2.1 is so clearly positioned as offering new UHBR speeds everywhere you look, making this optional could (and will) lead to confusion. In our opinion, UHBR should be a requirement, and manufacturers should have to list the UHBR speed alongside the DP 2.1 branding.
Other DisplayPort 2.1 Features
On top of mandatory requirements, DP 2.1 has introduced optional features that manufacturers may or may not choose to take advantage of, such as VESA’s Panel Replay capability, which improves power efficiency by reducing power consumption when the display is displaying a static image most of the time.
Elsewhere on their website they talk about MST support which is apparently now a standard feature of DP 2.1. “A multi-monitor setup can increase productivity and seamless multi-tasking at work, and create a massive, immersive experience for gaming. DisplayPort Certified products with Multi-Stream Transport (MST) allow for multiple screens (at various resolutions) to be driven from a single DisplayPort source connection, using either a DP hub, or by daisy-chaining monitors with that capability. While MST has been an optional capability since version 1.2, DisplayPort 2.0 / 2.1enables MST by default.”
VESA also tell us that “there are other, more subtle updates (e.g., data structure clarification/addition, metadata definition extension) with each new standard version that improve the interoperability as well as the visual quality even at lower than the maximum link rate. That is why there is an obvious merit for a product to be certified to the latest version of DisplayPort standard, irrespective of its maximum link rate.”
At this time VESA unfortunately do not have a clear list of required vs optional features for each iteration of DP although they tell us they are reviewing ways to make this clearer for consumers in the future. We’d like to see more detail on which other features are available and possible from DP 2.1.
There is No New or Different DisplayPort Logo for DP 2.1 Devices
According to a May 2022 press release promoting the first compatible products for DP 2.1 “product developers who take advantage of the DisplayPort UHBR Certification Program gain the ability to use the VESA Certified DisplayPort logo on their products and become reference devices for end-use product interoperability testing.”
It was not really clear from the press release which DP logo they were talking about, and how this might be different for devices certified under the DisplayPort 2.1 scheme, as compared with older certified products. We queried this with VESA and confirmed that there are unfortunately, and possibly confusingly, no separate logos between DP 1.2, DP 1.4 and DP 2.1. Nor are there any differences in logos between DisplayPort High Bit Rate 3 (HBR3) used for DP1.4 and Ultra High Bit Rates (UHBRs) used for DP2.0.
This means that while products may be certified against different DP generations (1.2, 1.4 and 2.0) and should therefore include that version listed in their specification, there is only one single DisplayPort logo available. As such, the logo on its own doesn’t really mean much or tell you anything about the device’s capabilities other than that it simply has a DP connection of some sort. You will need to refer to the spec sheet to identify the specific DP version being used, along with any of the features you may want to use.
VESA also say you can visit https://www.displayport.org/products-database/ for the latest list of VESA certified DisplayPort products, although this list isn’t clear which DP version or certification they are certified against or any of the capabilities it might have.
What to Look Out for When a Screen is Listed as Having DisplayPort 2.1
VESA’s guidance when determining which features are available is that vendor packaging and on-line information should indicate the DisplayPort features supported for each product. That keeps it simple, although it does mean that like HDMI 2.1 you cannot make assumptions about capabilities based purely on the “DisplayPort 2.1” badge. We’ve also seen from the above discussion that you sadly cannot assume that a device labelled as DP 2.1 even supports any of the new UHBR speeds that are widely associated with this new standard and that you’d probably take for granted as being included. That makes life particularly difficult.
The things you should look out for (and the thing we hope manufacturers list when DP 2.1 devices become available) are:
We will have to wait for the first DP 2.1 displays to be announced and released to see how manufacturers tackle this, but these are the things you’d ideally want to be able to see from the spec.
DisplayPort 2.1 Certification Programme and Testing
The DisplayPort 2.1 UHBR certification programme was launched in February 2022. Through the DisplayPort UHBR Certification Program, device and cable manufacturers can send new products to DisplayPort authorized test centers (ATCs) for testing and certification
In May 2022 VESA announced that the first video source and display devices supporting the new DisplayPort UHBR (Ultra-high Bit Rate) – the higher data link rates supported by the DisplayPort standard version 2.0 – have completed certification through the DisplayPort UHBR Certification Program. To achieve this important milestone, UHBR chipset reference source and display designs provided by AMD, MediaTek and Realtek successfully met the PHY, link and interoperability testing requirements outlined in the DisplayPort 2.1 Compliance Test Specification (CTS). At this stage these are just chipsets and prototype products but it provides a positive step forward towards future DisplayPort 2.1 graphics cards and monitors for instance.
VESA also announced that qualified VESA DisplayPort Authorized Test Centers (ATCs) are ready to begin testing and certification of UHBR end-products using approved test equipment and reference sink and source devices for interoperability testing. This means the test centres are good to go as manufacturers begin to product source devices, and displays with the new connection type.
An engineering demonstration of a reference source and sink device setup from AMD and MediaTek operating at UHBR link rates was showcased earlier in the year at the Display Week Symposium and Exhibition in San Jose, Calif. in May 2022.
“These latest developments in the DisplayPort UHBR Certification Program represent major steps forward in the roll-out of the DisplayPort UHBR ecosystem for new video, display and cable products supporting higher resolutions and refresh rates,” stated James Choate, compliance program manager for VESA. “Certification of UHBR reference devices must undergo rigorous testing to ensure they meet the requirements outlined in the DisplayPort 2.0 CTS. We’re excited to announce that a set of reference silicon has been verified to meet the requirements of the DisplayPort 2.0 spec through our certification program. VESA now has the testing infrastructure in place to evaluate and certify OEM end products, and we are ready to work with the ecosystem to bring next-generation DisplayPort chipsets and IP to market.” (from before the update to DP 2.1 standard)
MediaTek, AMD and Realtek all involved in creating DP 2.1 UHBR devices
The following quotes were from earlier in 2022 before the DP 2.1 update was announced on 17 Oct 2022
“We are very proud to be the first DisplayPort adopter to achieve DisplayPort UHBR certification for a sink device,” said Vince Hu, corporate vice president and general manager, Compute Business Unit, MediaTek Inc. “With the features that DisplayPort 2.0 brings to the table, we are able to develop advanced, robust technologies that system manufacturers can leverage to revolutionize the consumer’s highest quality visual experience. VESA requires very stringent testing before certification can be granted, making MediaTek’s achievement even more impressive. We are honored to play a critical role in VESA’s efforts to ensure interoperability and deliver industry leading products to market.”
“We are delighted to continue our deep collaboration with VESA on developing the DisplayPort 2.0 UHBR ecosystem through use of AMD Ryzen™ 6000 Series processor as a certified reference source device,” said Syed Athar Hussain, VESA board vice-chairman and AMD CVP and display domain senior fellow. “The DisplayPort UHBR Certification Program will ensure sources, cables, and displays interoperate seamlessly and build a robust ecosystem that delivers the full potential of DisplayPort 2.0 UHBR technology. UHBR rates defined by the DisplayPort standard represent a new paradigm for display connectivity, with unprecedented bandwidth to facilitate smooth gaming, efficient video playback, and greater than 8K-resolution professional displays.”
Yee-Wei Huang, spokesperson and vice president of the Multimedia Business Group at Realtek, stated, “We are proud to announce that our first DisplayPort 2.0 Rx solution and DisplayPort 2.0 Tx solution have passed VESA’s UHBR Certification Program. This will help customers to quickly achieve end-product certification as part of the VESA interoperability compliance testing program. With the new Realtek DisplayPort 2.0 Rx/Tx solutions, an end user can enjoy a more responsive and better resolution display on multiple display applications. This offers a significant leap forward that can satisfy both commercial and consumer markets as high quality monitors and docking stations continue to evolve.”
DisplayPort 2.1 Cable Certification
DP 2.1 still uses the same physical connection as older generations, but you will need a cable that can support the new UHBR if you have an actual UHBR device, and want to use DP 2.1 properly. VESA also have a separate certification scheme for compatible cables which has a fairly simple structure thankfully, and this time there is an associated logo scheme which should in theory make it easy to select an appropriate cable. Why is it so much simpler for cables than for devices?!
The scheme will certify UHBR cables under DP40 and DP80 tiers as explained below:
DP40 Cables – UHBR10 link rate (10 Gbps x4 lanes = 40 Gbps)
VESA certified DP40 cables must support up to the UHBR10 link rate (10 Gbps) defined by DisplayPort 2.1, and support the full four-lane operation, providing a maximum throughput of 40 Gbps. Hence the “DP40” name.
DP80 Cables – UHBR20 link rate (20 Gbps x4 lanes = 80 Gbps)
VESA certified DP80 cables must support up to the UHBR20 link rate (20 Gbps) defined by DisplayPort 2.1, with four lanes, providing a maximum throughput of 80 Gbps. VESA certified DP80 cables will also support the UHBR13.5 link rate (13.5 Gbps), which is also defined by DisplayPort 2.1.
Several DP40 and DP80 cables using improved full-sized DisplayPort and Mini DisplayPort connectors have already passed certification and are in production. Vendors currently producing VESA certified DP40 and DP80 cables include Accell, BizLink, and Wieson Technologies, with more cables undergoing certification and expected to arrive to market soon. BizLink were the first to release a DP80 cable as discussed on their website here.
No matter how high the performance of your graphics card and monitor are, the resulting image quality can still be limited by the cable used to connect those devices. Thanks to improvements in both the DisplayPort connector and cable design, the new VESA certified DP40 and DP80 UHBR cables enable consumers to get the highest performance possible from their VESA certified devices. These new cables are backed by VESA’s UHBR Certification Program, which provides added assurance that if your cable has the DP40 or DP80 logo from VESA, it will meet the specs for the highest data rates supported by current and future products certified by VESA.
DP40 and DP80 cables are available in both full-size and Mini DisplayPort cable configurations, and are fully backward compatible with devices supporting DisplayPort link rates previously defined and currently in use, including RBR (Reduced Bit Rate), HBR (High Bit Rate), HBR2, and HBR3 in older DisplayPort generations up to v1.4. For DisplayPort Alt Mode (DisplayPort over the USB Type-C connector), full-feature passive USB-C cables already support UHBR bit rate speeds, while USB Type-C to DisplayPort converter cables certified by VESA to meet UHBR speed requirements will soon become available according to VESA.
With the updates to DP 2.1 made on 17 Oct 2022 VESA have also updated the DisplayPort cable specification to provide greater robustness and enhancements to full-size and Mini DisplayPort cable configurations that enable improved connectivity and longer cable lengths (beyond two meters for DP40 cables and beyond one meter for DP80 cables) without diminishing UHBR performance.
What if your cable isn’t good enough and isn’t DP40 or DP80 certified?
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.
Thankfully the certification and logo scheme for DP 2.1 cables should make it simple to find an appropriate cable to support the UHBR speed you need, and we would expect display manufacturers to start shipping suitable cables with their monitors in the future when DP 2.1 is featured too.
Update to DP v2.1 from v2.0 Summary
This article was originally published on 12 Oct 2022, and less than a week later VESA announced that they had replaced DP 2.0 with DP 2.1. This is the latest version of the DisplayPort specification, which is backward compatible with and supersedes the previous version of DisplayPort 2.0. Thankfully this is just a straight forward replacement in the version number, with all devices that were previously certified as DP 2.0 being updated to DP 2.1. Is it merely a coincidence that this will now be DP 2.1, when the current version of HDMI is also 2.1?! Convenient if nothing else.
“VESA has been working closely with member companies to ensure that products supporting DisplayPort 2.0 would actually meet the newer, more demanding DisplayPort 2.1 spec. Due to this effort, all previously certified DisplayPort 2.0 products including UHBR (Ultra-high Bit Rate) capable products – whether GPUs, docking station chips, monitor scalar chips, PHY repeater chips such as re-timers, or DP40/DP80 cables (including both passive and active, and using full-size DisplayPort, Mini DisplayPort or USB Type-C connectors) – have already been certified to the stricter DisplayPort 2.1 spec.”
What has been updated with DP 2.1?
“Achieving greater alignment between DisplayPort and USB on a common PHY has been a particularly important effort within VESA given the significant overlap in use case models between the DisplayPort and USB4 ecosystems,” stated Alan Kobayashi, VESA Board Chair and VESA DisplayPort Task Group Chair. “DisplayPort 2.1 brings DisplayPort into convergence with USB4 PHY specifications to ensure the highest video performance across a broad range of consumer products...”
Put simply, all DP 2.0 certified devices are now DP 2.1 compliant already, but the newer DP 2.1 standard will provide better and stricter criteria for future devices and development.
When will DisplayPort 2.1 be Available?
We have yet to see any commercially available graphics cards announced from NVIDIA that have DP 2.1, even with their RTX 4000 series launched in Autumn 2022. Intel do have their A770 card which can support UHBR10 apparently, although seems to be pending certification and presumably also testing under the latest DP 2.1 standards. On 3 November 2022 AMD announced their new RX 7900 XT and XTX graphics cards which will be the first high end gaming graphics cards to feature the new DP 2.1 connection, including some of the new capabilities.
The AMD RX 7900 XT and XTX cards will support UHBR 13.5 for a total 54Gbps bandwidth, at least including some of the new UHBR speeds which is good news, and extending beyond DP 1.4 and even HDMI 2.1 bandwidth capabilities. AMD talked in their press release about how this could in theory enable displays with 4K 480Hz, 8K 165Hz and even 1440p 900Hz thanks to the use of DSC. Obviously there aren’t any such displays yet, but this does at least open the door to them being developed. We would expect to see the next generation of NVIDIA cards including DP 2.1 and over time the bandwidth capabilities should increase to the full 80Gbps UHBR20 too.
At the AMD RX 7900 XT / XTX launch event, AMD also teased what was expected to be the first DisplayPort 2.1 capable monitor. It was referred to as the ‘Samsung Odyssey Neo G9’ at the event which is actually an existing model, although since CES 2023 in January we now know that this is an updated version which will carry a different product name when it’s released. This will be the Samsung Odyssey Neo G95NC and is a massive 57″ super ultrawide screen. This was showcased at CES by Samsung, and also by VESA as part of their DisplayPort 2.1 promotion. This screen has a massive 7680 x 2160 resolution and 240Hz refresh rate, operating using UHBR 13.5 bandwidth link rates.
“AMD is delighted to collaborate with Samsung and VESA to demonstrate the next generation of high-resolution, high-refresh, high-fidelity visual experiences enabled by DisplayPort 2.1 products across gaming, productivity, and professional segments,” said Syed Athar Hussain, VESA board vice-chairman and AMD CVP and display domain senior fellow. “Pairing our VESA DisplayPort 2.1-certified AMD Radeon RX 7900 Series graphics cards with Samsung’s Odyssey Neo G9 showcases a premium ultra-smooth, low-latency, high-refresh gaming experience at 8K2K DUHD 240Hz with UHBR13.5. We are excited for users to experience these upcoming products for themselves, and they can be confident that source, sink, and cable interoperability will be assured by the VESA UHBR Certification Program.”
AMD also said that Acer, Asus, Dell and LG are all working on DP 2.1 capable monitors to be announced in 2023. For other monitors featuring DisplayPort 2.1, keep an eye on our news pages.
There’s clearly a lot of potential with DisplayPort 2.1 with a huge 3x bandwidth increase over DP 1.4 opening up a whole new world of resolution and refresh rate combinations that we can’t wait to see launched. The possibilities for future displays are certainly exciting. In recent times HDMI has over-taken DP in supported bandwidth but when DP 2.1 finally arrives this will put this connection back in pole position when it comes to PC connectivity (for now).
The capabilities are impressive, but while there are some aspects of the certification and standards that we agree with, there are others which we find hard to justify. It’s definitely sensible for devices to still be certified under older DP 1.2 and 1.4 standards if that’s all they support, and that avoids everything just being labelled as DP 2.1 in the future. We would have liked a new logo to make it quick and simple for consumers to differentiate which version of DP is featured on a given device, as the current “one logo fits all” approach is a bit pointless. Cable selection is thankfully nice and simple, with a clear certification, naming and logo scheme to support it. Nice work on the logo side from VESA.
Our main issue with the new standard is the rather odd certification approach that means that officially a device doesn’t even need to support the new UHBR to pass as DP 2.1 and earn that badge! When the high bandwidths and new speeds are the absolute number 1 thing being promoted by VESA, and being talked about by every media outlet covering DP 2.1, this should be a baseline requirement. Everyone is going to expect a DP 2.1 device to feature new speeds beyond DP 1.4 at the absolute least. In our opinion, if a device doesn’t support UHBR it shouldn’t be calling itself DP 2.1.
There is at least the possibility here that manufacturers will be transparent with their specs, and will list the speeds, features and capabilities the device supports clearly. But this whole thing feels like a rather unnecessary complication when really UHBR should have been mandatory. It’s all very well mandating DSC, and that’s certainly an excellent feature and opens up a whole world of possibilities, but why not make UHBR mandatory too?
Time will tell how DP 2.1 is promoted when it starts to appear on graphics cards, monitors and other devices in the future and we will update this article whenever we get any new useful information.
We may earn a commission if you purchase from our affiliate links in this article- TFTCentral is a participant in the Amazon Services LLC Associates Programme, an affiliate advertising programme designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com, Amazon.co.uk, Amazon.de, Amazon.ca and other Amazon stores worldwide. We also participate in a similar scheme for Overclockers.co.uk, Newegg, Bestbuy and some manufacturers.
Stay Up To Date
|Browser Alerts||Follow us on X (Twitter)||Subscribe||Support Us|
Popular Trending Articles