Don’t Buy an HDMI 2.1 TV or Monitor Before You Read the Fine Print

Don’t Buy an HDMI 2.1 TV or Monitor Before You Read the Fine Print
Photo: Wes Davis/Gizmodo

Just like USB, SD, and other ports, not every HDMI input is the same, and using the right one could have a marked effect on things like picture quality, frame rates, and latency.

If deciphering every version of HDMI wasn’t already tedious enough, we now know that the latest and greatest HDMI 2.1 standard, well, isn’t very standardised. A TFTCentral investigation revealed that the TV or monitor you purchase with “HDMI 2.1″ might not support any of the latest features.

TFTCentral smelled something fishy when it saw that a Xiaomi monitor with HDMI 2.1 support only reached the specifications for HDMI 2.0. Instead of 4K resolution, the panel was limited to 1080p. And the thing is, Xiaomi technically didn’t do anything wrong. It all comes down to semantics and some murky (and consumer-hostile) guidelines set by the HDMI Licensing Administrator.

In this case, Xiaomi was compliant in the eyes of the HDMI gods for burying this small endnote within the terms and conditions: “Due to the subdivision of HDMI certification standards, HDMI 2.1 is divided into TMDS (the bandwidth is equivalent to the original HDMI 2.0 and FRL protocols). The HDMI 2.1 interface of this product supports the TMDS protocol, the maximum supported resolution is 1920×1080, and the maximum refresh rate is 240Hz.”

Now we’re getting into the technical weeds but, in short, HDMI 2.0 is a subset of HDMI 2.1, meaning its specifications are housed within the newer standard. The standards organisation even said it would no longer certify for HDMI 2.0, telling TFTCentral that HDMI 2.0 “no longer exists” and that the features and capabilities of HDMI 2.1 are optional. As long as a monitor supports one of the newer standards, it can be called HDMI 2.1.

As you’d expect, HDMI 2.1 consists of many standards, so TV and monitor makers could theoretically grab the lowest hanging fruit, add it to their (formerly) HDMI 2.0 ports, and slap an HDMI 2.1 label on the box.

The HDMI standards body even confirmed to The Verge that what Xiaomi is doing is perfectly within the rules and that we all depend on manufacturers to be honest about their products. The problem is that they rarely are.

History tells us that even reputable brands will do whatever they can to use the latest buzzwords to push products out. We’ve seen mobile carriers weasel their way into using pseudo 4G and 5G labels, TV brands selling sets with HD compatibility but without the resolution to display it, and monitors from household names claiming to deliver HDR despite not supporting the official standard.

It’s a frustrating scenario for consumers, who these standards bodies should be prioritising. Now seeing HDMI 2.1 listed in the specs for a TV doesn’t necessarily mean it can support resolutions of up to 10K, bandwidth at 48Gbps, and Dynamic HDR. And while these were always only theoretical features, we had incorrectly assumed the existence of a minimum threshold we could take comfort in. Now the minimum includes HDMI 2.0 specs and could mean a maximum supported resolution of only 1080p.

HDMI 2.1 has made headlines in recent months because of the capabilities it enables on next-gen consoles and gaming PCs — specifically, the ability to run 4K games at 120Hz. You miss out on those benefits if you don’t have the right connection and high-speed HDMI cable. Now, even if you think you have the right setup, you might not.