If you haven’t already noticed, HDMI’s latest specification (HDMI 2.1) is starting to find its way into more and more big name consumer electronics, such as PlayStation 5, Xbox Series X, and a range of new televisions. It’s no surprise why, either. The range of improvements HDMI 2.1 offers over HDMI 2.0 are significant, to say the least, and they’re designed to get the most out of things like 4K and High Dynamic Range (HDR).

If you’re a home entertainment specialist or installer, understanding the nuts and bolts of HDMI 2.1 is now essential if you want to help your customers get the most out of their devices.

What is HDMI 2.1?

HDMI 2.1 is the most recent specification developed by the HDMI Forum’s Technical Working Group. It was first released in 2017 and is now starting to gain wider relevance and usage in new consumer electronics.

HDMI 2.1 offers major improvements over the more common HDMI specifications of HDMI 2.0 and HDMI 1.4b, including increased bandwidth and smoother Ultra HD video at higher frame rates.

HDMI 2.1 dramatically increases the bandwidth of HDMI to 48Gbps (from 18Gbps), allowing it to support 4K video at a frame rate of 120fps, 8K video at 60fps. It also offers support for 10K video. Click To Tweet

4K and HDR video and streaming become standard for home theaters, newer devices such as gaming consoles, televisions, and high-end PC graphics cards are adopting HDMI 2.1. The increased bandwidth demands of the latest home entertainment systems benefit from a central distribution hub such as the latest Primex Soho range of enclosures.

HDMI 2.1 vs. HDMI 2.0 and HDMI 1.4

The upgrade from HDMI 1.4 to HDMI 2.0 was significant but limited. While both supported 4K video, HDMI 2.0 introduced a higher bandwidth of 18Gbps and support for 4K video at a frame rate of 60fps (HDMI 1.4 was limited to 4K video at 24fps).

HDMI 2.1 improves on this yet again, as well as introducing several other enhancements that will not only help home entertainment enthusiasts get the most out of their systems, but also future-proof them for newer devices down the road.

HDMI 2.1 dramatically increases the bandwidth of HDMI to 48Gbps (from 18Gbps), allowing it to support 4K video at a frame rate of 120fps, 8K video at 60fps. It also offers support for 10K video.

Additionally, HDMI 2.1 supports Dynamic HDR (High Dynamic Range) in 4K at 120fps. HDR isn’t new and is also supported by HDMI 2.0 but Dynamic HDR improves on static HDR by adjusting the colour palette frame-by-frame in minute detail to deliver the best possible picture.

Another key enhancement that will be particularly noteworthy for installers and pros is improved support for eARC (Enhanced Audio Return Channel). With HDMI 2.1, eARC can work with a single HDMI cable and turn supported devices into true passthroughs, letting you simplify and streamline the setup with fewer cables.

For a deeper look at the range of enhancements HDMI 2.1 offers, you can explore the explainer page on HDMI Forum.

How to Identify HDMI 2.1 Devices

One wrinkle with HDMI 2.1 is the lax rules around what manufacturers can label as being an HDMI 2.1 device. Currently, a device only needs to offer a single HDMI 2.1 feature rather than all of them to say it supports HDMI 2.1.

If you’re planning a home entertainment system for a customer, or planning an upgrade to existing one, make sure you’re fully aware of which HDMI 2.1 enhancements the devices you’re recommending or installing provide.

Which HDMI Cables to Use With HDMI 2.1

In similar vein, it’s critical to ensure you’re using the correct HDMI cables if you want to get the most out of HDMI 2.1 devices.

HDMI cables will not state which specification they support, as HDMI’s licensing body prohibits it. Instead, cables are certified at certain speeds. For HDMI 2.1 devices, you’ll need to use an HDMI Ultra High-Speed Certified Cable, which supports 48Gbps. These are distinct from Premium High Speed cables, which will not support the enhanced features that HDMI 2.1 offers.

HDMI 2.1 devices will still work with older HDMI cables but they will not support the range of improvements provided by HDMI 2.1.

To ensure you’re using the correct HDMI cables you can download the official HDMI Cable Certification app (iOS | Android) and scan the QR code on the cable before you buy it.