HDMI vs DP Interfaces: The Age Beyond Speed

Technology realized through interface

Advanced display technologies such as HDR10+ images, 8K resolution, VRR (variable scan rate), and eARC can only be implemented when delivered through interfaces. Without transmission interface to carry supporting signals, light cannot be displayed even if high-performance panels are installed. For example, HDMI 2.2 offers broad content compatibility and audio transmission (eARC), while DisplayPort 2.1 offers ultra-high scan rates and bandwidth optimized for multi-display configurations.

Although display manufacturers are deliberate in selecting HDMI or DP interfaces according to their product objectives and target consumer, they are still often questioned about their interface adoption and implementation choices whenever a product moves from the design to certification stage.

*Manufacturers who wish to receive guidance on certification may consult Granite River Labs (GRL) for practical tips on how to leverage environments and data from the perspective of an accredited certification laboratory.

Selecting product-specific interface strategically

Transmission speed aside, complex strategic decisions account for the suitability of use cases, ecosystem compatibility, and authentication procedure requirements for real-world implementation.

For example, premium TVs and home theatres send audio to eARC and ensure HDR10+ content compatibility based on HDMI 2.2 designs, with key test items in HDR performance implementation being EDID processing and dynamic metadata verification. Gaming monitors, on the other hand, adopt DisplayPort 2.1 to implement ultra-high scan rates and AdaptiveSync capabilities of 240Hz or higher. Notably, signal integrity must be precisely verified when multiple display daisychains are connected.

HDMI and USB-C in laptop and mobile devices further require complex test scenarios such as Alt Mode transition or power transmission (PD) collision. Finally, vehicle displays are often designed with embedded HDMI interface to withstand harsh temperature and vibration environments, especially since the durability of built-in connectors can greatly influence signal integrity.

As such, the interface is not just a connection terminal, but a key variable that determines the product's functional implementation and authentication strategy. Appropriate test strategies can help ensure that a product’s interface works according to design intention rather than resulting in authentication failure.

FAQs on site

Q: “Why do TVs use HDMI instead of DP?”
A: TVs operate within a robust HDMI-based ecosystem that encompasses set-top boxes, consoles, and soundbars. This isn’t a matter of technical specifications alone, but consideration of practical factors such as chipset availability, user habits, and market distribution structures. By taking this into account, GRL verifies HDMI-based products to seamlessly implement features like eARC, HDR10+, and CEC, supporting manufacturers in making the right decisions for their products.

Q: “Isn’t USB-C a universal connector?”
A: Although USB-C may seem like the ideal all-in-one port that integrates data transfer, display output, and power delivery, implementation often remains challenging due to complex design issues such as power delivery (PD), signal interference, and ultra-high refresh rate video processing. Through verification of USB-C’s DP Alt Mode operation, PD negotiation and conflicts, heat generation, and signal stability is necessary to ensure that this “all-in-one” port performs as intended.

Q: “Which port is the best for multi-display?”
A: DisplayPort’s advantage lies in how it allows multiple screens to be connected in series via a single port (daisy chaining). Regardless, issues such as resolution limitations, interference noise, and signal degradation can still arise. The critical factor lies not in the connection itself, but whether performance remains stable after connection. Testing and verifying must therefore go beyond simple functional connectivity to ensure that there are no performance degradations owing to interface adoption.

The next interface wave – Unified, Wireless, and Secure

1. Accelerating USB-C-based integration: With rapid adoption of USB4, DisplayPort Alt Mode integration, and single-port designs such as Converged I/O (CIO) architectures, single USB-C port product designs are increasing to handle data transfer, power supply, and display signal output. Furthermore, the expansion of System-on-Chip (SoC) solutions that integrate multiple functions into a single chipset is expected to significantly transform manufacturing processes and performance optimization.
2. Growth of Wireless Display: Wireless display technologies based on Wi-Fi 6E and Wi-Fi 7 are also beginning to be adopted. As demand in conference and living rooms increases, cable management becomes more and more crucial. But even as experimental applications for greater user convenience continue, meeting full bandwidth and stability requirements of ultra-high resolution and ultra-high refresh rate environments remains a challenge. Ultimately, while wireless display has significant potential, it will likely remain a complementary solution limited to specification applications for the foreseeable future.
3. The continued centrality of wired interfaces: Despite technology’s rapid advancement, HDMI and DisplayPort are expected to remain dominant in the display interface field. These interfaces don’t just boast large ecosystems and proven compatibility, but also stable chipset supply chains and a trusted array of accreditations. Particularly in environments that demand the highest performance such as premium TVs, gaming, monitors, and workstations, the aforementioned wired interfaces remain as the overwhelming favorites. Ultimately, products that win out are the ones that meet performance, reliability, and certification standards, regardless of technological advancement.

Reliable hands-on support for a successful product launch

Interface selection remains a complex strategic decision that goes far beyond chasing after the latest specification. Product line, target market, user experience, and connectivity with the existing ecosystem must all be factored in to launch a reliable and trusted product to market.

As a VESA and HDMI Forum accredited test laboratory, GRL provides comprehensive technical support services ranging from interoperability testing, problem cause analysis, and design optimization. Choose the best interface for your product with confidence when you gain clarity from GRL’s design roadmap.

For more information on GRL’s certification and display technology testing services, visit the links below:

• HDMI certification test services
• Learn more about DisplayPort certification test services