HDMI (High Definition Multimedia Interface) is a high-definition multimedia interface widely used in various electronic devices, including laptops. The HDMI interface not only provides high-quality audiovisual transmission but also greatly simplifies the connection between digital devices. With HDMI on a laptop, it’s easy to connect the computer to various displays.

Today, HDMI has become one of the mainstream audiovisual interfaces for laptops, with HDMI 2.1 being the latest standard. While HDMI 2.1 offers a range of exciting features and improvements, there are still some potential risks and challenges in the market, with compatibility issues being the most troublesome. If manufacturers are not careful in product development, it could seriously affect consumer purchasing intentions and even lead to return risks.

HDMI has become one of the mainstream audiovisual interfaces for laptops, with HDMI 2.1 being the latest standard.


Compatibility Issues and Potential Risks of HDMI 2.1

For many years, Allion has closely collaborated with numerous industry clients. When the industry adopts the 2.1 specification design, if clients encounter compatibility issues based on market feedback, they also commission Allion to provide subsequent technical support. Leveraging its extensive experience and deep understanding of specifications, Allion can assist clients in swiftly identifying the root cause of problems.

To address the insufficient space of the screen EDID, HDMI 2.1 introduced the EEODB framework to replace the original Block Map. If the 2 blocks EDID cannot meet the screen’s resolution, users can choose to use Block Map or EEODB to add blocks, thereby writing in more resolutions.

To address the insufficient space of the screen EDID, HDMI 2.1 introduced the EEODB framework to replace the original Block Map.

Since the launch of HDMI 2.1 three years ago, Allion has relied on its experience in certification testing to observe that when EDID space is insufficient, most clients have opted to abandon the old Block Map architecture in favor of the new EEODB framework. However, it wasn’t until August 2021 that the HDMI Consortium officially listed EEODB testing as a mandatory item. This means that HDMI laptops prior to this may have been unable to recognize the screen’s EEODB framework, leading to the inability to output certain resolutions.


How can HDMI 2.1 compatibility issues be improved?

In response to the proliferation of HDMI 2.1 compatibility potential risks in the market in recent years, the Allion consulting team suggests the following proactive solutions that manufacturers can adopt:


Solution 1: Supplementary Testing for Certification Items

For laptops that were already on the market before August 2021 and thus have not undergone HDMI-certified EEODB testing, there might be compatibility risks when these laptops are connected to screens using EEODB, potentially resulting in the inability to output certain resolutions. Therefore, to ensure the proper functioning of EEODB features, Allion recommends clients conduct supplementary testing for certification items. Additionally, it’s worth noting that graphics card manufacturers can typically enable laptop support for EEODB through firmware/software updates.


Solution 2: Additional EEODB Testing for HDMI 2.1

The EEODB feature is defined in the HDMI 2.1 Spec. This means that if the laptop specification only supports HDMI 1.4, there is no need to perform EEODB testing. However, the EEODB framework is not defined solely for writing HDMI 2.1 resolutions; it’s also possible to write HDMI 1.4 resolutions. Therefore, we suggest that even if laptops only support up to HDMI 1.4, clients should consider adding EEODB testing during certification to ensure optimal compatibility.


Faster, Easier, Better! Allion HDMI Certification and Test Service

As an officially authorized certification testing laboratory by the HDMI Forum, Allion has accumulated years of rich experience and project achievements in the industry. We not only meet the needs of customers for quickly obtaining HDMI certification but also effectively shorten the design verification time. We assist clients in ensuring product performance and compatibility in a faster, easier, and better manner, thus reducing the risk of product recalls and returns.

  • Comprehensive HDMI Compliance Test Solutions: Through certification testing, products can avoid being audited by HDMI and ensure signal transmission quality.
  • Customized Test Planning Services: By conducting compatibility testing and user scenario simulation testing, we ensure the normal operation of link functions between products.



With proficient testing techniques and extensive practical experience, Allion can provide fast and accurate third-party assessments, helping clients effectively shorten design verification time. We also possess a rich and comprehensive range of HDMI devices to ensure product compatibility, ensuring quality control for your products.

  • Extensive Equipment and Verification Experience: We can quickly provide verification plans.
  • Assisting Clients in Obtaining HDMI Standard Certification Quickly.
TeledyneLecroy QD980 HDMI2.1 Protocol Analyzer
TeledyneLecroy QD980 HDMI2.1 Protocol Analyzer



Allion possesses a complete set of HDMI hardware verification equipment and testing environments. Through our testing solutions, Allion ensures that each verification assessment exhibits the characteristics of “qualitative, quantitative, and reproducible.” We assist you in simplifying the process and enhancing the quality and overall performance of your products.

  • Obtain more accurate test results in a simpler manner.
  • Provide professional Issue Isolation and Debugging Support, assisting clients in completing product development more conveniently.



The Allion technical team, comprised of experts in relevant technical fields, understands how to design quantitative testing methods and user experience verification. They ensure that your product meets regulatory requirements while also meeting user expectations, allowing your product to perform effectively in real-world applications. Allion can also provide product modification suggestions and apply specifications from various international associations to the product development process, assisting clients in further enhancing product quality to meet international standards.

  • Assisting clients in establishing supply chain quality management.
  • More comprehensive user scenario simulation testing.

Allion Labs_Faster, Easier, Better


If you have any testing, verification needs related to HDMI compatibility, please feel free to browse the following services or contact us through the online form.

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