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Guide to DisplayPort 2.1: How to get the most out of the new Ultra-High Bit Rate (UHBR) transmission modes

By Aaron Yip - 6 Feb 2024

Guide to DisplayPort 2.1: How to get the most out of the new Ultra-High Bit Rate (UHBR) transmission modes

At CES 2024, Gigabyte presented the “world’s first” OLED gaming monitor that features a DisplayPort 2.1 Ultra-High Bit Rate (UHBR) 20 mode. You’re probably familiar with the terminology DisplayPort, but what exactly is UHBR 20? Well, before I answer that let’s go a little way back and understand DisplayPort better.

When it comes to picking a video cable to connect our gaming PC to our viewing screens of choice, there are only two choices: DisplayPort and HDMI. These two connecting sources have been the go-to choices for PC/console gamers and movie aficionados for nearly two decades. Their latest revision, DisplayPort 2.1 and HDMI 2.1b come packed with support for the latest and greatest AV specifications; namely 4K and 8K support, high refresh rates, a range of HDR standards, and 10-bit color, as well as compression technologies like display stream compression and chroma subsampling.

I’ll talk more about HDMI and its latest 2.1 version in a separate piece because today it’s all about DisplayPort and the new UHBR 20 transmission mode and why it matters for PC users.

Wait, what is DisplayPort?

A typical DisplayPort cable. Image: VESA

Uh oh. Ok, for the benefits of tech beginners. Once upon a time…

Introduced as a successor to the aging VGA and DVI standards, DisplayPort has carved out its niche as a preferred digital interface for transmitting video from desktop PCs to monitors, while also handling audio and data transmission. Its inception was aimed at modernising the connection landscape, offering a bridge to the past with backward compatibility to older standards like VGA, DVI, and HDMI through adapters.

DisplayPort often finds itself in comparison with HDMI, which is positioned as its competitor. It boasts superior bandwidth capabilities, yet it doesn't mirror HDMI's extensive feature set. Since its debut in 2006, DisplayPort has evolved across several generations. However, it wasn't until DisplayPort 2.1's introduction that we witnessed a significant leap forward from DisplayPort 1.3, which had been the standard since 2014. While DisplayPort 1.4 focused more on enriching features rather than boosting performance, it remains the prevalent choice found in numerous modern graphics cards (such as NVIDIA’s GeForce RTX 40 series) and monitors.

Sporting a distinctive 20-pin, non-reversible connector, DisplayPort includes a locking mechanism to ensure a secure connection – a thoughtful design aspect, albeit with its quirks. The Mini DisplayPort variant, lacking this locking feature, has been pretty much phased out, overtaken by the more common and versatile USB-C. USB-C's adoption of DisplayPort Alternate mode exemplifies the interface's flexibility, allowing it to carry video and audio alongside data over a single cable to compatible displays.

Is Display 2.1 the latest version?

Yup, as of this time of writing it is.

Interestingly, the leap from DisplayPort 1.4 to 2.1 is monumental, primarily because the DisplayPort 2.0 standard was never adopted in any consumer device, making 2.1 the debut platform for the advancements initially envisioned for 2.0, along with some additional enhancements. These improvements are aimed at standardising the performance of high-speed DisplayPort cables and to better integrate the DisplayPort protocol with USB-C connectivity. The last part is key, as it could theoretically mean that future DisplayPort cables and ports could look like USB-C ones.

Ok I get it but what can Display 2.1 do for me?

The short and quick answer is a lot of bandwidth.

DisplayPort 2.1 triumphs with a bandwidth capacity that triples what was achievable with DisplayPort 1.4. This leap is made possible by the introduction of three new transmission modes: Ultra High Bit Rate 10 (UHBR 10), Ultra High Bit Rate 13.5 (UHBR 13.5), and Ultra High Bit Rate 20 (UHBR 20). These modes refer to the data rate per lane, which, when multiplied by the four lanes typical of DisplayPort connections, results in a staggering potential bandwidth of 80 Gbps. This figure not only nearly doubles what HDMI 2.1 can offer but also rivals the top speeds of USB4 Type-C cables.

Transmission Mode Certification Level Bandwidth
UHBR 10 DP40 or DP80 40 Gbps
UHBR 13.5 DP 54 or DP80 54 Gbps
UHBR 20 DP80 80 Gbps

While it's true that not all DisplayPort 2.1 cables, devices, or displays will support these advanced transmission modes, even the base UHBR 10 mode places DisplayPort in the upper echelon of video transmission capabilities. For instance, devices connected via UHBR 10 can deliver 4K visuals at a refresh rate of up to 144Hz, or 8K at 30Hz. Go up all the way to UHBR 20 and we are looking at 4K at up to 240Hz or 8K at an incredible 85Hz – all of these without any kind of compression (e.g., Display Stream Compression or DSC).

The impact of DisplayPort 2.1 extends beyond just ultra-high resolutions; it significantly enhances the potential for higher refresh rates at lower resolutions as well. It's capable of pushing 1440p up to 500Hz, or 1080p up to an astonishing 900Hz. Such capabilities will very likely herald a new generation of ultra-blazing fast esports gaming monitors, although I’m not sure if our eyes will be able to notice differences at that kind of speed but that’s a topic for another time.

DisplayPort 2.1 will also require new DP40 or DP80 cables. Image: VESA

Moreover, DisplayPort 2.1 could also significantly benefit next-generation VR and AR headsets by providing the higher resolution and refresh rates essential for a more immersive and comfortable experience.

Unfortunately, DisplayPort 2.1 does not have features in the same mold as HDMI's popular ARC and eARC capabilities, but it introduces a novel bandwidth management feature that enhances the simultaneous transmission of data and video over USB-C. Additionally, with new testing and naming protocols for the higher bandwidth DP40, DP54 and DP80 cables, DisplayPort 2.1 sets a new standard in video transmission technology.

So I should get a monitor that supports Display 2.1?

Well, if you’re looking for a new monitor then it’s probably for the best that you pick one that supports it (like the Gigabyte 32-inch Aorus FO32U2P), so as to future-proof your new and expensive purchase. Even though the only consumer grade graphics cards that support it are AMD’s Radeon RX 7000 series (which supports UHBR 13.5), it’s very much expected that NVIDIA will almost certainly include Display 2.1 for its next generation of graphics cards. Just be sure to keep an eye out for DP40, DP54 and DP80 certified cables, as these will guarantee the bandwidth you need.

For more information about DisplayPort 2.1, click here.

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