Wondering how next-gen AV interfaces HDMI 2.1 and DisplayPort 1.4 stack up? Our comprehensive guide examines the specs, capabilities and performance of both to help you decide which is best for your needs.
Introduction to The State of The Art in Display Connectivity
HDMI 2.1 and DisplayPort 1.4 represent the leading edge in interfaces for transmitting ultra high definition video and audio signals between media sources and displays.
HDMI 2.1 – Released in 2017 by the HDMI Forum, HDMI 2.1 builds on prior HDMI specs by increasing bandwidth to 48 Gbps and adding new capabilities around 8K video, 4K/120Hz gaming, dynamic HDR and more. It’s backwards compatible with earlier HDMI ports and cables.
DisplayPort 1.4 – Introduced in 2016 by the Video Electronics Standards Association (VESA), DisplayPort 1.4 focuses more on driving high resolution computer monitors and gaming displays. Improvements include 32.4 Gbps signaling to support 8K video, better HDR support and increased reliability over longer cables. DisplayPort 1.4 is also backwards compatible with previous DisplayPort generations.
Both HDMI 2.1 and DisplayPort 1.4 represent the current state-of-the-art in display interface technology. But each takes a somewhat different approach based on their heritage and primary applications.
In this guide, we’ll compare the specifications, features and real-world capabilities of these interfaces to help explain their differences and assist you in choosing the right display connectivity solution.
Historical Background
HDMI and DisplayPort emerged at different times to serve complementary needs in the display ecosystem:
HDMI first appeared in 2003 as a unified connection to handle both audio and video in home theater and entertainment devices. It evolved to support higher resolutions, wider color gamuts, 3D video and audio return channel (ARC) functionality. Each iteration brought more performance aimed at consumer video applications.
DisplayPort arrived in 2006 to provide a robust interface for computer monitors and GPU connectivity. Designed with scalability in mind, DisplayPort offered display daisy-chaining and high resolutions suitable for computing use cases. As desktop monitor needs grew, DisplayPort increased capabilities through new versions to handle faster signaling rates, higher resolutions and standardized features.
The table below shows the evolutionary progress of each standard:
| Year | HDMI Version | DisplayPort Version |
|---|---|---|
| 2003 | 1.0 | – |
| 2006 | – | 1.0 |
| 2009 | 1.4 | 1.2 |
| 2013 | 2.0 | 1.2a |
| 2016 | – | 1.4 |
| 2017 | 2.1 | – |
This brings us to the current HDMI 2.1 and DisplayPort 1.4 interfaces which represent the state of the art in the evolution of each standard.
HDMI 2.1 vs. DisplayPort 1.4 – Specification Comparison
So what exactly changed in the latest versions of HDMI and DisplayPort? Below we dig into the updated technical specifications for each standard:
| Specification | HDMI 2.1 | DisplayPort 1.4 |
|---|---|---|
| Maximum Bandwidth | 48 Gbps | 32.4 Gbps |
| Maximum Video Resolution | 10K @ 120Hz | 8K @ 60 Hz |
| 4K Resolution Support | 4K @ 240Hz | 4K @ 120Hz |
| Chroma Subsampling | 4:4:4 | 4:4:4 |
| HDR Metadata Format | Static & Dynamic | Static |
| Enhanced Audio Return Channel | Yes | No |
| Ethernet Channel | Up to 100 Mbps | No |
| Display Streams Per Cable | 1 | Up to 4 |
| Cable Length | Up to 3m (~10 ft) | Over 15m |
| Max Pixel Clock Rate | 1,008 MHz | 810 MHz |
| Color bit depth | Up to 16-bpc | Up to 10-bpc |
| HDCP Support | 2.3 | 2.3 |
Key Takeaways
- HDMI 2.1 supports significantly more bandwidth at 48 Gbps vs. 32.4 Gbps for DisplayPort 1.4. This allows higher resolutions at faster refresh rates.
- HDMI 2.1 specifies resolutions up to 10K @ 120 Hz whereas DisplayPort 1.4 currently supports up to 8K @ 60 Hz.
- DisplayPort 1.4 impresses with robust signal integrity allowing cables over 15m. HDMI 2.1 cables longer than around 3m usually require fiber optic solutions.
Real-World Display Feed Bandwidth Requirements
But what do these bandwidth numbers mean for actual display configurations? Below we calculated the interface bandwidth required for common resolutions and refresh rates:
| Resolution | Refresh Rate | DisplayPort 1.4 Bandwidth | HDMI 2.1 Bandwidth |
|---|---|---|---|
| 720p | 60 Hz | 2.23 Gbps | 2.23 Gbps |
| 1080p | 60 Hz | 3.19 Gbps | 3.19 Gbps |
| 4K | 60 Hz | 10.94 Gbps | 10.94 Gbps |
| 4K | 120 Hz | 21.88 Gbps | 21.88 Gbps |
| 8K | 30 Hz | 23.84 Gbps | 23.84 Gbps |
| 8K | 60 Hz | 47.68 Gbps | 47.68 Gbps |
We can observe that both HDMI 2.1 and DisplayPort 1.4 provide enough headroom for most common media feeds. However, 8K video starts to push the limits of what DisplayPort 1.4 can handle.
HDMI 2.1‘s extra bandwidth headroom allows support for resolutions up to 10K and use cases like 4K playback at 240 Hz for super smooth gaming.
Key Feature Comparison
Beyond pure specifications, we also need to examine the type of functionality provided by both interfaces.
HDR Support – All major HDR standards are covered between HDMI 2.1 and DisplayPort 1.4. However HDMI 2.1 ratchets up performance with:
- Dynamic HDR metadata capable of scene-by-scene adjustments
- Support for Dolby Vision profile 8.1‘s 12 bits per color RGB/4:4:4 signal format
- Higher luminance levels up to 10,000 nits
This gives HDMI 2.1 better overall HDR format coverage and quality.
Audio Transport – HDMI 2.1 builds on robust audio capabilities by incorporating enhanced audio return channel (eARC) support. This allows lossless passage of Dolby Atmos and DTS:X surround sound from TV apps over a single cable without extra hardware.
DisplayPort 1.4 lacks ARC functionality so a separate audio connection is needed alongside the video cable.
Power Delivery – DisplayPort 1.4 specifies more power delivery downstream to compatible displays. This allows for monitor features like USB-C/Thunderbolt 3 connectivity and daisy-chaining without separate power bricks. Maximum delivery jumps substantially from 14W in HDMI 2.0b to 100W in DisplayPort 1.4.
Content Protection – Both standards incorporate the latest HDCP 2.3 copy protection. Additionally DisplayPort 1.4 implements 128-bit AES encryption for the video signal when using standard transport mode. This helps defend against unauthorized signal sniffing.
Compatibility and Cable Certification – DisplayPort 1.4 requires certification of both cables and devices to ensure interoperability. HDMI 2.1 device testing is also mandatory but cables are optional. Overall DisplayPort’s approach promotes reliability over a wider selection of connectivity products.
Pros and Cons Comparison
| HDMI 2.1 Pros | – Higher 48 Gbps bandwidth headroom above current display feed requirements | – Backwards compatibility with tens of millions of deployed HDMI devices |
|---|---|---|
| – Dynamic HDR support allows fine-tuning of picture quality | – Ubiquitous input across all modern 4K/8K smart TVs | |
| – Enhanced audio return channel for lossless surround sound passthrough | – HDMI Ultra High Speed cables ensure 48 Gbps speeds |
| HDMI 2.1 Cons | – Maximum ~3 meter cable spec length without special optical HDMI cabling | – Optional cable certification potentially allows poorly made cables |
|---|---|---|
| – Only supports one display per cable |
| DisplayPort 1.4 Pros | – Signaling robustness allows cables beyond 15 meters | – Mandatory cable certification promotes interoperability |
|---|---|---|
| – Up to four monitors on one GPU via daisy-chaining | – Higher power delivery to displays | |
| – Strong AES 128-bit video encryption | – Pure hardware-based processing avoids compatibility issues |
| DisplayPort 1.4 Cons | – Slightly lower maximum bandwidth vs. HDMI 2.1 | – Lacks audio return channel support present in HDMI |
|---|---|---|
| – Uncommon among smart TVs with only one input |
Recommendations
- For home cinema, we recommend HDMI 2.1 to leverage cutting-edge TV capabilities and robust audio return channel support
- For PC gaming and productivity setups, we suggest DisplayPort 1.4 to enable multi-display configurations from a single graphics card
- Utilize active adapters between HDMI and DisplayPort standards for interfacing unmatched source and display interfaces
Overall both standards represent best-in-class connectivity for current 4K and 8K media setups. We hope this detailed examination has cleared up their differences and assists in designing your optimal configuration. Let us know if you have any other questions!
Frequently Asked Questions
Q: Which has better gaming performance – HDMI 2.1 or DisplayPort 1.4?
A: Both support variable refresh rate (VRR) for smooth, tear-free gaming. HDMI 2.1 offers higher resolutions up to 4K/240Hz while DisplayPort 1.4 enables multi-display gaming rigs. For most gamers, performance will be spectacular on either interface.
Q: How do the HDR capabilities compare between the two standards?
A: All major HDR 10 standards are covered. However HDMI 2.1 ratchets up quality with Dynamic HDR metadata adjustment along with Dolby Vision profile 8.1 support. DisplayPort 1.4 tops out at static metadata HDR 10. So HDMI 2.1 delivers better overall HDR.
Q: What cable connection issues might I run into with HDMI 2.1 or DisplayPort 1.4?
A: HDMI 2.1 signals degrade rapidly after ~10 feet, requiring special 48 Gbps optical cables for longer runs. DisplayPort 1.4 utilizes DSC signal compression which enables copper cables beyond 15 meters without issue. Poorly made HDMI 2.1 cables can also cause problems which DisplayPort helps avoid via mandatory certification.
Q: Will HDMI 2.1 work with my older HDMI cables and devices?
A: Yes, HDMI 2.1 is designed to be fully backwards compatible with earlier HDMI ports and cables. You can seamlessly mix and match HDMI 2.1 sources with older TVs and receivers.
I hope this fully details the comparison between both advanced display interfaces! Please let me know if you have any other questions.
