It turns out that “HDMI 2.1” ports don’t have to support HDMI 2.1 features.

If you dabble in high-end 8K TV gear or own one of the latest Xbox or PlayStation consoles, you may be familiar with HDMI 2.1. The latest version of the ubiquitous display specification adds support for variable refresh rates, reduces latency, and offers a significant increase in bandwidth, resulting in higher resolution, higher refresh rates, and greater color depth. At least he can support these things.

It turns out that TV and monitor manufacturers don’t actually need to support these outstanding HDMI 2.1 features to claim HDMI 2.1 compatibility. This is the crux of the TFTCentral report, which indicates that the HDMI 2.1 specification actually replaces the HDMI 2.0 specification entirely, rather than just updating it. So any manufacturer that supports HDMI 2.0 level features technically supports “HDMI 2.1″because the HDMI 2.0 specification no longer exists. And the features we think of when we talk about HDMI 2.1, including Fixed Rate Signaling (FRL), Variable Refresh Rate Support (VRR), Automatic Low Latency Mode (ALLM), and Enhanced Audio Return Channel (eARC), are technically desire.

“Products can no longer be certified for version 2.0 only for version 2.1, and 2.1 features are not mandatory to implement, so popular features such as 4k120, ALLM, VRR are not required,” confirmed Brad Bramy, VP of marketing and operations of HDMI LA. to Ars. “Manufacturers could only implement eARC, for example, and claim they support 2.1.”

Manufacturers claiming HDMI 2.1 support are required by the HDMI Adopter Agreement to clearly state which HDMI 2.1 features their devices support, although Bramy acknowledged that this can still be “confusing to consumers”and that individual manufacturers are ultimately liable. for people to know what they are getting. This confusion is exacerbated by the fact that the “HDMI 2.0″terminology is still widely used, although it is technically obsolete.

“I think some older 2.0-certified products will just keep theirs.. . marketing intact,” Bramy said. “Some [manufacturers] unfortunately think that even if they are 2.1 certified, they still have to link to 2.0 if they haven’t implemented 2.1 features, believing that 2.0 is a known set of features. Also equally confusing is the conformity statement in 2.1. and still use feature sets from version 2.0 and do not specify supported features. Thus, there are several scenarios, and all of them can be confusing. And that’s why manufacturers and resellers should just state what features they support. I can tell that it’s getting bigger as time goes by, but I’m not sure it will ever be completely clear.”

While this HDMI 2.1 situation is just getting underway, none of these facts are technically new – some searches on the Internet Archive Wayback Machine confirm that the HDMI 2.0 section was removed from the hdmi.org website sometime between February 6th and 13th. . 2019. But there was a period when both specs did co-exist on the website, and the November 2017 press release (PDF) announcing the HDMI 2.1 spec didn’t mention that HDMI 2.0 would go away. It’s also not how the HDMI Forum handled the transition from HDMI 1.4 to HDMI 2.0, and it’s not how most companies and developers handle it when they release a new version of something.

There is one precedent for this, although no one should emulate it: The USB Developers Forum has been constantly appending new version numbers to older versions of the USB specification, which started when “USB 3.0″became “USB 3.1 Gen 1”. many years ago. The USB-IF has since elevated this practice to a performance art with absurd names like “USB 3.2 gen 2×2″and “USB 3.2 gen 1″(which is also USB 3.0).

This kind of naming trick is an obvious advantage for OEMs, who can claim support for the latest version of a spec even though they don’t technically support all of the latest and greatest features in that spec. These manufacturers have a strong presence in the HDMI and USB-IF Forum, both as members and as part of the leadership of the former organization. But for people who are just trying to buy things that support the features they want, this behavior continues to be confusing at best and deliberately misleading at worst. You can look at Dell, HP, Lenovo and Acer.product pages and look up four different terms for the same type of port: “USB 3.0”, “SuperSpeed ​​USB 5Gbps Data Transfer Rate”, “USB 3.2 gen 1″and “USB 3.1 gen 1″respectively. All of these are currently (or used at various times) perfectly valid ways of designating a port of this type.

The situation with HDMI 2.1 isn’t too bad so far, but if the HDMI forum continues to introduce “new”version numbers that retroactively apply to older versions of the standard, we’ll end up in the same place. For now, you just have to be especially careful when buying HDMI 2.1-labelled monitors and TVs if you’re interested in 8K, HDR, higher refresh rates, and other HDMI 2.1 features. Some companies are also taking it upon themselves to clarify which products support all HDMI 2.1 features, as Microsoft did with its “Xbox Game Features”monitor labels. But in the long run, I’m again asking the standards bodies to just let the version numbers mean something.