Why Am I Having 8K Compatibility Issues? Your HDMI Cable Might be the Culprit

The Latest in HDMI 2.1

8K televisions are the latest in-home entertainment technology, incorporating the most recent HDMI 2.1 specification, which has increased its bandwidth capabilities up to 48 Gbps and supports 8K60, 4K120, and even resolutions up to 10K.

HDMI 2.1 also incorporates new features that bolster image quality and bring gaming experiences to all new heights. New HDMI 2.1 cables offer dynamic HDR, enhancing image quality and color depth by rendering the image throughout the video, frame by frame.

HDMI 2.1 also improves video quality with enhanced refresh rates to improve the smoothness of the image, specifically for video, movies, and gaming. New features include Variable Refresh Rate (VRR) to reduce or eliminate lag during gameplay, Quick Media Switching (QMS) to help eliminate delays in screen display upon connection, Quick Frame Transport (QFT) to help reduce latency for less lags in gaming, and Auto Low Latency Mode (ALLM) to automatically establish the most fitting latency setting for smoother images.

Because of these newly added features focusing on smoother and more vibrant video experiences, gamers will be inclined to use 8K supported televisions and HDMI cables, but it’s quickly becoming apparent that even if a television supports 8K, a bad HDMI cable can cause major compatibility issues.

Obtaining an 8K Connection Might Not Be as Easy as They Say

A video circulating in the tech world, “They SAID this would be EASY... - Gaming at 8K 60fps”, by Linus Tech Tips, shows a complicated but rather humorous account of Linus attempting to connect a new Sharp 8K TV to a gaming system, which is supposedly as easy as “plug and play”, but he quickly realizes that it may not be as simple as it is made out to be.

During the video, we see a back forth conundrum of trying various different set ups to correct the connectivity issues that arise as he tries to establish a quality image. However, even after multiple attempts, connecting the 8K TV to the gaming system still proved to be unattainable. What ends up finally solving the connectivity issues was swapping out the cables to include a native HDMI to DisplayPort cable, rather than including adapters within the setup. While using the adapters should technically work the same, it goes to show that certain cables simply do not always perform as expected, even when they are certified.

Although video sources and 8K televisions can often appropriately handle the latest HDMI 2.1 specification, HDMI cables can still cause major interoperability issues, resulting in poor image quality, or even none at all.

Why do even certified cables not always function as expected?

Why is that some HDMI cables, even ones that are certified, cause image and sound issues? These issues typically stem from within the development and production process. With many added variables including the potential for human-error while assembling cables, replicating a perfect cable each time is almost impossible; and while many cable manufacturers test their cables off the production line, they typically only perform functional testing, meaning they plug the cable into a television, and if it displays an image, it is considered to pass.

This type of functional testing is not stringent – the aforementioned variable refresh rates and resolutions used to ensure the picture always looks smooth for the consumer could compromise resolution to maintain smoothness. That means the simple appearance of an image on the test screen is not necessarily a guarantee that the cable actually meets the HDMI 2.1 specification for bandwidth; human eyes in a factory environment wouldn’t discern a 2K picture from a 4K picture from an 8K picture. Furthermore, simply just obtaining cable certification does not guarantee that each individual cable is up to standard during the actual production process. Below the surface, there are many components within the cable that need to be tested that include ensuring all pins and wires are correctly assembled, measuring the DC resistance of the cable, and verifying the signal quality.

Many manufacturers do not always look to ensure these are up to standard, mainly due to the high cost of testing and expensive overhead. Total Phase has introduced a product, the Advanced Cable Tester v2, to combat this known issue happening within cable factories.

The Advanced Cable Tester v2 allows for production quality control with its complete set of testing.

The Advanced Cable Tester v2 Allows for Production Quality Control

The Advanced Cable Tester v2 is a one-stop cable tester that will allow users to determine the quality, safety, and cable functionality with just one tool and a one-time test. Once a user plugs in the cable, they can quickly determine in just a few seconds if the cable is up to standard. Our comprehensive tests include pin continuity testing preventing shorts and opens, DC resistance measurements for non-data lines, and signal integrity testing up to 12 Gbps. Our enhanced signal integrity testing also provides eye-diagrams and includes masks per the appropriate insertion loss cable specification, and if any portion of the eye diagram touches the mask, the cable will be flagged as a failure.

Because we’ve designed this tool to be a cost-effective cable testing solution in a high output environment such a cable factory, individual quality control is now feasible. Taking the right measures to perform individual quality control using the Advanced Cable Tester v2 will allow complete assurance of quality while also offering low cost consumables during the testing process.

The Advance Cable Tester v2 tests video cables including HDMI and DisplayPort cables:

HDMI Type A to HDMI Type A (HDMI 2.1 and earlier version specifications) using the HDMI-A to HDMI-A Connector Module

ACT v2 Connector Module: HDMI-A to HDMI-A allows testing of HDMI cables with the Advanced Cable Tester v2

DisplayPort to DisplayPort (DisplayPort 2.0 and early version specifications) using the DisplayPort to DisplayPort Connector Module

ACT v2 Connector Module: DisplayPort to DisplayPort allows testing of DisplayPort cables with the Advanced Cable Tester v2.

For more information on how the Advanced Cable Tester v2 can help you achieve individual quality control or other testing requirements in your environment, please email us at sales@totalphase.com.