When was DisplayPort Released?
DisplayPort 2.1 was released in 2022 and was adopted by a couple of products on the market, namely the new AMD Radeon RX7000 and AMD Radeon PRO W7000 Series GPUs. A big value proposition for these GPUs is the future-proofing for displays, adding DisplayPort 2.1 alongside the existing HDMI 2.1 port. While still new, there aren't many devices that support DisplayPort 2.1. In this blog, we will discuss the key differences in DisplayPort 2.1 including bitrate, peak resolutions, peak refresh rates, and relevance to HDMI 2.1.
Quick Background on Display Connectors DisplayPort and HDMI
HDMI, arguably the more popular sibling, is an audio-visual interconnect developed in 2002 to replace and improve upon DVI, combining video and audio in a smaller unified port. It also ended up replacing VGA, red, yellow, white Component, and other forms of video output cables. HDMI became the de facto standard for connecting media devices to a video output.
DisplayPort or DP is also an audio-visual interconnect developed in 2006 to replace the blocky white and block blue DVI and VGA cables on computers and monitors. It differs from HDMI by using a packetized data transmission, a form of digital communication used in Ethernet, USB, and PCIe. From the start, DisplayPort has always been able to deliver more data, thus supporting higher resolutions at higher refresh rates than HDMI. DP is more common on just PCs and Laptops connecting to computer monitors.
What is DisplayPort 2.1
DisplayPort 2.1 is the newest iteration and a major improvement to the widely used DP 1.4 by supporting triple the total bandwidth thanks to new transmission modes UHBR 10, UHBR 13.5, and UHBR 20. Ultra High Bit Rate numerical values denote the per-lane data rate of the connection, which in DP is multiplied by 4 lanes.
Transmission Modes | Certification Level | Bandwidth | Data Rate | DP 1.4 | DP 2.1 |
|---|---|---|---|---|---|
RBR (1.62 Gbit/s) | Standard VESA-Certified | 6.48 Gbit/s | 5.18 | ✅ | ✅ |
HBR (2.70 Gbit/s) | Standard VESA-Certified | 10.80 Gbit/s | 8.64 | ✅ | ✅ |
HBR2 (5.40 Gbit/s) | Standard VESA-Certified | 21.60 Gbit/s | 17.28 | ✅ | ✅ |
HBR3 (8.10 Gbit/s) | DP8K Cable | 32.4 Gbit/s | 25.92 | ✅ | ✅ |
UHBR10 (10 Gbit/s) | DP40 Cable | 40.00 Gbit/s | 38.69 | ❌ | ✅ |
UHBR 13.5 (13.5 Gbit/s) | DP80 Cable | 54.00 Gbit/s | 52.22 | ❌ | ✅ |
UHBR 20 (20 Gbit/s) | DP80 Cable | 80.00 Gbit/s | 77.37 | ❌ | ✅ |
The increased bit rate transmitted over the DP 2.1 enables higher resolutions, increased HDR, and support for even higher refresh rates. Since the data transfer rates are still capped, there is a tradeoff between resolution and refresh rate at uncompressed. Below is a table of resolutions and the refresh rates each type of DisplayPort can handle based on speed and protocol. We used common refresh rates, with pluses to signify that the peak is beyond current monitor technology limits.
Peak Resolutions | HBR3 (DP 1.4) | UHBR 10 | UHBR 13.5 | UHBR 20 |
|---|---|---|---|---|
1080p (1920x1080) | 500Hz | 500Hz+ | 500Hz+ | 500Hz+ |
1440p (2560x1440) | 240Hz | 360Hz | 480Hz | 500Hz+ |
4K (3840x2160) | 120Hz | 144Hz | 240Hz | 300Hz |
5K (5120x2880) | 60Hz | 60Hz | 120Hz | 180Hz |
8K (7680x4320) | 30Hz | 30Hz | 60Hz | 60 - 85Hz |
DisplayPort 2.1 is a new technology and was effectively only launched at the end of 2022 with the debut of AMD’s RX 7900 XT and 7900 XTX graphics cards. At the time of writing, they are the only DisplayPort 2.1 supported devices and monitors are just as scarce; if you want to use DisplayPort 2.1 in early 2023, there aren't many options. But, DP 2.1 can be utilized with very large, high resolution, multi-displays plugged into the same port via multi-stream transport or MST, but that multi-display setups can also be delivered using a video wall controller.
Compared to HDMI 2.1
There was a time when DisplayPort 2.1 didn't exist and HDMI 2.1 reigned as the fastest video connector. HDMI 2.1 is the newest standard with a maximum bandwidth that went from 18Gb/s (from HDMI 2.0) to 48 Gb/s. Without compression, HDMI 2.1 can deliver resolutions up to 4K 144Hz and 8K 30Hz, performing admirable to the previous generation DP 1.4. However, with the newest iteration, DisplayPort once again is back on top for the most capable video connector.
That isn’t to say it is practical… DP 2.1 is still extremely new with just AMD GPUs supporting the format. HDMI 2.1 supports higher bandwidth than DP 1.4 and since the lifespan of HDMI 2.1 has allowed monitor manufacturers to support it, HDMI 2.1 is objectively the better option if you’re running the fastest monitor uncompressed with HDR.
We will have to wait until more displays and GPUs utilize the full bandwidth of DP 2.1 and the higher UHBR 10, UHBR 13.5, and even the overkill UHBR 20 standards. After all, as panels have higher and higher resolutions and refresh rates, there are diminishing returns on what the human eye can see and perceive when looking at such crisp and fast monitors. It would be awesome to see 4K 240Hz monitors start to surface, only possible with DisplayPort 2.1 UHBR 13.5 and up.