We all know good old HDMI. For quite some time, it has been the typical cable you use to connect a laptop, a game console, or a cable or satellite box to a TV.

Nowadays, though, our old buddy can do much more than that, especially once you factor in the HDMI 2.1 specification. This latest HDMI spec has been bandied around for a couple of years now (hit the link for our earlier primer on it), but the latest consumer electronics are only now starting to support the new standard. And 2.1 brings with it some exciting "today" improvements—plus some future-looking potential—over existing HDMI specifications.

Major devices that support it include the big two new gaming consoles (the Microsoft Xbox Series X and the Sony PlayStation 5), leading-edge gaming graphics cards (including the Nvidia GeForce RTX 3080 and the AMD Radeon RX 6800XT), and a wide range of TVs. That said, HDMI 2.1 isn't a front-line feature that gets advertised, or explained, with most PC and consumer-electronics gear. Indeed, you may not see the term at all in a store or when shopping online, even when looking at gear or cabling that supports it. (More about that in a bit.) Let's get into how HDMI 2.1 works, and help you decide whether your next big tech purchase should include it.

The Basics: HDMI Versus DisplayPort

Before we get into HDMI 2.1 specifics, let’s put the spotlight on DisplayPort, HDMI’s main rival for carrying a cutting-edge display signal these days. Both connections support the same goal of providing audio and video over a single cable, though each has its focus area. HDMI is the home entertainment go-to for TVs and game consoles, while DisplayPort is a more common choice for connecting to PC monitors (though HDMI can be used for that, too).

(Image: PCMag)

Often, PC-centric display devices will support both HDMI and DisplayPort (providing inputs for both), so the choice then comes down to which one works best for your specific usage case. (See our feature HDMI vs. DisplayPort: Which Should I Use for My PC Monitor? for some guidance on that.) However, based on HDMI 2.1’s improvements, it is a better choice for home entertainment needs for some reasons that may be new to you. It's also working up some steam on the PC and console-gaming side.

The Big 2.1: The Improvements From HDMI 2.0 to HDMI 2.1

The HDMI specification has gone through several revisions. HDMI 2.0, the immediate predecessor of HDMI 2.1, was announced in 2013, but it didn’t see widespread adoption until several years later, when 4K TVs finally began filtering into the mainstream. HDMI 2.0’s claim to fame over its last major HDMI-version predecessor, HDMI 1.4, was its support for "4K60"—that is, supporting 4K (3,840-by-2,160-pixel) video playback at a smooth 60 frames per second (fps). That frame-rate limit was 30fps with HDMI 1.4.

But that’s all—smoother video playback—that HDMI 2.0 truly brought to the table, versus prior HDMI versions. It was an important step, to be sure, but today’s media demands an even-higher-bandwidth solution for a more enjoyable and refined viewership experience.

Let’s dive into the features one by one. One key thing to know: HDMI 2.1 devices need to support only one of the following features to be advertised as an HDMI 2.1 device. That’s a potential concern for buyers who are depending on more than one of these new features, or on a specific one being present. (More on that later.)

Smoother, Higher-Resolution Video

HDMI 2.1 looks toward the future with its support for up to a 10K (10,240-by-4,320-pixel) native resolution. Now, no TVs or PC monitors support a resolution that high just yet. (And never mind the question: Where would you get 10K content?) HDMI 2.1’s more immediate benefit will be support for "4K120," which is 4K video at up to 120fps.

(Image: HDMI Licensing Administrator)

Near-term, this could be a boon for a subset of demanding PC and console gamers. These days, among serious players, 60fps is the more-or-less acce...