HDMI 2.1 vs DisplayPort 1.4: Bandwidth Against Features
Quick answer / TL;DR: Short answer: HDMI 2.1 carries 48 Gbps raw, about 42.6 Gbps payload after 16b/18b encoding, and reaches 4K120 10-bit and 8K60 with DSC. DisplayPort 1.4 carries 32.4 Gbps raw, 25.92 Gbps payload, and reaches 4K120 8-bit without DSC. For a desktop monitor, DisplayPort 1.4 is usually sufficient and often cheaper.
Four versions, four bandwidth ceilings: the cable must match the signal.On paper HDMI 2.1 wins: 48 Gbps against 32.4 Gbps. In practice the two interfaces are used for different things, and the choice is usually made by the display rather than by the cable. Monitors almost always have DisplayPort, televisions almost always have HDMI, and the interesting cases are the ones where both exist.
The comparison only becomes useful once encoding overhead is removed and the supported feature sets are compared. Raw bandwidth is the starting point, not the answer.
Payload After Encoding
| Interface | Raw | Encoding | Payload | 4K120 10-bit |
|---|
| HDMI 2.0 | 18 Gbps | 8b/10b | 14.4 Gbps | no |
| HDMI 2.1 | 48 Gbps | 16b/18b | 42.6 Gbps | yes |
| DisplayPort 1.3 | 32.4 Gbps | 8b/10b | 25.92 Gbps | no |
| DisplayPort 1.4 | 32.4 Gbps | 8b/10b | 25.92 Gbps | no |
| DisplayPort 2.1 UHBR10 | 40 Gbps | 128b/132b | 38.7 Gbps | yes |
HDMI 2.1 uses a more efficient encoding, which is part of why its usable payload is so much higher. 4K at 120 Hz with 10-bit colour needs about 39 Gbps, so HDMI 2.1 clears it without compression while DisplayPort 1.4 needs DSC to get there.
Features That Differ
Variable refresh rate
Both support it, under different names. HDMI 2.1 has VRR as part of the specification and AMD FreeSync works over it. DisplayPort has Adaptive-Sync as an optional part of the standard, which is the basis for FreeSync and G-Sync Compatible.
Audio return
HDMI has eARC, a dedicated reverse audio channel capable of high-bitrate formats. DisplayPort has no audio return path at all. If a soundbar or AV receiver is in the chain, HDMI is the only option.
Cable length
At their maximum rates, both are limited to short passive runs. HDMI 2.1 at 48 Gbps is practical to about 3 metres passively, and longer runs need active or fibre cables. DisplayPort 1.4 at HBR3 reaches about 2 metres passively.
The Port Labelling Trap
HDMI 2.1 permits manufacturers to implement a subset of features and still call the port 2.1. A television with a 2.1 port may support 4K120 but not 8K, or support eARC but not VRR. DisplayPort has no equivalent practice: a 1.4 port supports the 1.4 feature set.
When buying a display, read the feature table rather than the version number. The specific questions are: does this port do 4K120, does it do VRR, and does it do eARC.
Real-World Applications
Desktop PC with a 4K 144 Hz monitor
DisplayPort 1.4 with DSC enabled is the standard configuration, and it is cheaper than an HDMI 2.1 chain. If the monitor supports HDMI 2.1 at full rate, either works, but the DisplayPort path has fewer compatibility surprises.
Console on a television
HDMI 2.1 only. Consoles output HDMI, and the television's eARC handles the audio. The cable needs to be Ultra High Speed certified for 4K120.
Laptop to a projector
HDMI, because projectors rarely have DisplayPort. The projector is usually 4K30 or 1080p, so an 18 Gbps cable is enough and a 48 Gbps cable adds nothing.
Workstation driving two 4K60 displays
Two DisplayPort 1.4 links, one per display, rather than MST. Separate links avoid the shared-payload compromise and remove a failure point.
Related reading: HDMI 2.1 versus 2.0 — blogs/news/hdmi-2-1-vs-2-0
Related reading: DisplayPort 1.2 versus 1.4 — blogs/news/displayport-1-2-vs-1-4
Related reading: HDMI cable length limits — blogs/news/hdmi-cable-length-limit
Standards and Verification
HDMI 2.1 is published by HDMI Licensing Administrator, with the electrical specification defining 48 Gbps over four lanes using 16b/18b encoding, plus Fixed Rate Link training. DisplayPort 1.4 is published by VESA, with HBR3 at 8.1 Gbps per lane and 8b/10b encoding.
Both organisations run certification programmes with searchable product databases. For HDMI, Ultra High Speed cables carry a certification label with a QR code that resolves to the database entry. For DisplayPort, VESA maintains a list of certified cables and displays.
Verification on a running system is the same for both: read the reported link rate and mode in the driver's display information panel. If a monitor capable of 4K144 reports 4K120, the limit is the interface or DSC support, not the cable. If it reports 4K60, check whether the cable is certified for the required rate before replacing anything else.
Frequently Asked Questions
Which is better for gaming?
For a monitor, DisplayPort 1.4 with DSC covers 4K144 and is the common choice. For a television, HDMI 2.1 is the only option.
Does HDMI 2.1 always mean 48 Gbps?
No. The specification allows a subset of features to be labelled 2.1, so a port may be limited to 4K120 or omit VRR.
Can I convert between them?
Passive adapters work in the HDMI-to-DisplayPort direction only in specific cases. Reliable conversion needs an active adapter, and eARC never survives conversion.
Is DisplayPort 1.4 enough for 8K?
Only with DSC and a reduced refresh rate. Practical 8K60 needs HDMI 2.1 or DisplayPort 2.1.
Does cable length matter more on one?
Both are limited at maximum rate. HDMI 2.1 at 48 Gbps is practical to about 3 metres passively; DisplayPort 1.4 HBR3 to about 2 metres.
Sourcing cables for a project, a store, or a private-label line? Contact our B2B sales team for specifications, certification evidence, and volume terms – FOB and CIF options available. Request a quote or sample.
