Which DisplayPort cable do I need: DP40, DP54 or DP80?

Buy the cable that matches the link rate your graphics card and monitor both support: DP80 for UHBR20, DP54 for UHBR13.5, DP8K for DisplayPort 1.4. In practice DP80 is only worth having on an RTX 50 card connected to a UHBR20 monitor, for a mode that needs more than about 52 Gbps, such as 1440p at 480 Hz without DSC. On any AMD RX 7000 or RX 9070 card, a DP54 cable (or a DP40 you already own) carries everything the port can send.

The five VESA cable certifications

VESA names its cable certifications by bandwidth, not by spec version. A box that says "DisplayPort 2.1" without one of these names does not tell you which link rate the cable was tested at.

VESA's DP8K announcement calls them cables "guaranteed to support DisplayPort High Bit Rate 3 (HBR3)", at 8.1 Gbps per lane. The DisplayPort 2.1 release introduced DP40 at UHBR10 and DP80 at UHBR20, and listed "longer cable lengths (beyond two meters for DP40 cables and beyond one meter for DP80 cables)" as work in progress. The DisplayPort 2.1a announcement added DP54, "with passive cable lengths of up to two meters", and said UHBR13.5 users "are no longer limited to connecting UHBR13.5 sink and source devices with a one-meter DP80 cable". The DP80LL announcement promises UHBR20 "over an active cable up to three meters in length", which it describes as up to three times the length of passive DP80.

The DP40 surprise

The fact most cable guides miss: a DP40 cable you already own is good for UHBR13.5. In the same 2024 announcement, VESA says "existing DP40 cables that have been shipped to date have been confirmed by VESA through rigorous testing to be compliant with the DP54 cable spec and support UHBR13.5 link rates." DP54 replaced DP40 as a certification. It did not make DP40 cables obsolete.

Which cable for which graphics card

A link runs at the lower of its two ends, so start with the card. NVIDIA's RTX 4090 spec page lists DisplayPort 1.4a. NVIDIA's RTX 50 announcement says Blackwell has "DisplayPort 2.1b UHBR20". Club386 lists the RX 9070 series at "DP 2.1a UHBR13.5" and notes the "lack of DisplayPort 2.1 UHBR20 support". AMD's own product page says only "DisplayPort 2.1a" and does not give the rate.

For the RX 7000 series, Wikipedia's spec summary gives "DisplayPort 2.1 UHBR 13.5 support (up to 54 Gbit/s bandwidth)". The UHBR13.5 payload is derived: DisplayPort.org states 77.37 Gbps for UHBR20, and we scale it by lane rate, the same way the DSC article derives UHBR10:

Which modes each cable carries without DSC

The data rates below are the ones we derived in the DSC and bandwidth article, at CVT reduced blanking v2. A mode fits a link if its rate is below the link's payload. If you are weighing 1080p at 540 Hz against 1440p at 360 Hz, the resolution guide covers what the extra pixels buy you.

"DP40 / DP54" means UHBR10 is enough on paper. Since DP40 cables are DP54-compliant, there is no reason to buy a UHBR10-only cable today. The interesting row is 1440p 360 Hz: at 10-bit it needs 49.2 Gbps, which fits UHBR13.5 with about 3 Gbps to spare. An AMD card on a UHBR13.5 monitor runs it uncompressed with a DP54 cable.

"DisplayPort 2.1 needs DP80" is half right

Two answers circulate: that any DisplayPort 2.1 setup needs a DP80 cable, and that any cable works. The first comes from 2022, when DP80 was the only certification above UHBR10 and UHBR13.5 users had to use a one-meter DP80 cable. VESA fixed that with DP54 in 2024. The second has nothing behind it that we could find: no VESA statement we read says an uncertified cable carries any given rate. Each certification exists because the cable is part of the link.

A DP80 cable on a UHBR13.5 card works, but you pay for bandwidth the port cannot use and accept a one-meter limit instead of two. If your desk needs more than a meter between card and monitor at UHBR20, that run means DP80LL.

The HDMI equivalent

HDMI.org certifies the Ultra High Speed HDMI Cable for "up to 48Gbps maximum bandwidth", the full HDMI 2.1 link. Premium High Speed cables are tested for "the full 18Gbps bandwidth". In the DSC article's table, HDMI 2.1 is what carries 1440p 360 Hz uncompressed at 8-bit, at 39.4 Gbps against 42.67 of payload. That needs the 48 Gbps cable. On an 18 Gbps cable it cannot run.

Where this stops applying

Lengths are what VESA states for certified cables, not a measurement of how far a signal reaches. We could not source a figure for uncertified cables at any length, so we give none. The mode rates assume CVT reduced blanking v2, and monitors with shorter blanking need a little less. If your mode runs with DSC, as 1440p 480 Hz on DisplayPort 1.4 must, it needs the cable for the link rate, not for the uncompressed rate. USB-C and Thunderbolt connections are left out on purpose: their limits depend on the port and the dock.

A faster cable does not make frames appear. Whether 480 Hz is worth chasing at all depends on your framerate, which the refresh rate guide and the FPS and refresh calculator answer.