Three link rates, three cable tiers
DisplayPort 2.1 sends data over four lanes, and each lane runs at one of three UHBR (ultra high bit rate) rates. The data rate is what's left after coding:
- UHBR10: 10 Gbps per lane, 40 Gbps over four lanes, 38.69 Gbps of data. Cable tier DP40.
- UHBR13.5: 13.5 Gbps per lane, 54 Gbps over four lanes, 52.22 Gbps of data. Cable tier DP54.
- UHBR20: 20 Gbps per lane, 80 Gbps over four lanes, 77.37 Gbps of data. Cable tier DP80.
The gap between the headline rate and the data is small because UHBR uses 128b/132b coding, about 3% overhead. DisplayPort 1.4's HBR3 uses 8b/10b, which takes 20%, so its 32.4 Gbps headline leaves 25.92 Gbps of data. Check which of the three rates a port lists, since the version number alone doesn't say. A cable has to be certified for the rate you want. DisplayPort 2.1b also added DP80LL active cables, which reach up to about 10 feet (3 m) at UHBR20.
What fits on each rate
UHBR10 is enough for 4K at 120 Hz in 10-bit full color, which needs 32.3 Gbps with CVT-RB v2 timing. At 240 Hz the same 4K mode needs 68.6 Gbps, and only UHBR20 carries that without compression.
8K at 60 Hz in 10-bit needs 62.1 Gbps. UHBR20 carries it uncompressed, while UHBR13.5 needs Display Stream Compression. For comparison, DisplayPort 1.4 can't carry 4K at 144 Hz in 10-bit, which needs 39.2 Gbps, without compression.
USB-C and Alt Mode
DisplayPort also runs over a USB-C port in Alt Mode. It can use all four lanes for up to 80 Gbps, or 40 Gbps while the cable also carries USB data. Which of that a given laptop or dock does depends on the device. The USB-C vs Thunderbolt for monitors page covers what each port can drive.
Versions and dates
DisplayPort 2.0 was released in June 2019, and 2.1 was announced in October 2022. DisplayPort 2.1a (January 2024) replaced the DP40 cable certification with DP54, which tests cables at UHBR13.5, and 2.1b (January 2025) added the DP80LL active cables. DisplayPort 2.1b also requires support for Display Stream Compression with forward error correction.