Overall Findings
The easiest way to understand the differences between HDMI 2.0 and 2.1 is HDMI 2.1 is the current standard of the audio/video format. Since its initial release in 2002, the High-Definition Multimedia Interface (HDMI) has received numerous version updates, and HDMI 2.1 is the most recent version release. Each subsequent version gets new capabilities or an increase in bandwidth. It means HDMI 2.1 has the most capabilities and highest bandwidth transmission rates of all HDMI versions.
Data Transmission Rates: HDMI 2.1 Offers Superior Speed
HDMI 2.1 introduced a new HDMI cable category called Ultra High Speed or 48G, due to the fact it supports bandwidth speeds up to 48Gbps. It’s nearly three times the bandwidth of HDMI 2.0 and effectively means HDMI 2.1 can output higher resolutions and faster refresh rates. You’ll also see boosts to HDR (High Dynamic Range), which removes video signal limitations to display a broader range of brightness and color on compatible displays. While HDMI 2.0 already supports HDR technology, HDMI 2.1 introduces “Dynamic HDR,” which adjusts HDR metadata on a frame-by-frame basis to help get even clearer images (especially in very bright or dark scenes).
Video: HDMI 2.1 Offers Faster Refresh Rates at Higher Resolutions
The most significant practical upside to HDMI 2.1 is in its video output. If you have a compatible TV, you’ll enjoy higher resolutions with faster refresh rates. Although HDMI 2.0 can output in both 4K and 8K resolutions, it can only do so at 60fps (frames per second) and 30fps, respectively. While you can still get an impressive picture with an HDMI 2.0 cable, it’s not ideal for displaying content requiring smooth motion, such as sports or video games. HDMI 2.1 can deliver much better video performance, including 4K resolution at 120fps and 8K at 60fps. It’s even future-proofed to support resolutions as high as 10K, though it will be some time before commercial sets adopt this capability. This resolution and frame rate bump makes HDMI 2.1 the cable of choice for next-gen gaming on consoles like the PlayStation 5 and Xbox Series X, both of which offer full HDMI 2.1 support. You’ll need to use an HDMI 2.1 cable to utilize either console’s full output capabilities (which also requires a compatible TV). Additionally, HDMI 2.1 introduces a few features to complement its higher resolutions and frame rates. VRR (Variable Refresh Rate) will adjust your display’s refresh rate in real-time to help eliminate stuttering and frame tearing in games. At the same time, QMS (Quick Media Switching) reduces delay while switching between video sources.
Audio: HDMI 2.1 Provides Minor Improvements
While the video benefits of HDMI 2.1 are significant, its audio improvements are minimal by comparison. HDMI 2.0 cables have a feature called Audio Return Channel (ARC), which enables audio to be sent back and forth along the same cable. HDMI 2.1 brings an incremental update to this technology with Enhanced Audio Return Channel (eARC), which essentially expands the range of audio codecs you can use, including Dolby Atmos and DTS:X. Of course, you’ll need audio equipment that supports eARC to take advantage of it. As things stand, HDMI 2.1 is the clear winner for serious audiophiles, but you won’t see much if any benefit unless you’ve recently upgraded your audio equipment.
Compatibility: 2.1 Is Backwards Compatible With Old Versions of HDMI
HDMI 2.1 cables are backward compatible, which means you can use them with devices that don’t support the 2.1 format. However, you can’t take advantage of the 2.1 features unless you have a compatible device and TV. For example, you can plug a PS5 into a TV with an HDMI 2.0 port using an HDMI 2.1 cable, and it will work fine. But you will only get 2.0 features since the cable will use the highest mode supported by all devices (in this case, it would be 2.0). By this point, HDMI 2.1 has arguably become mainstream, as most TV manufacturers have incorporated the standard into their product lines. That said, pay close attention to the port count on any new TV you buy, as some TVs come with a mix of 2.0 and 2.1 ports.
Final Verdict: HDMI 2.1 Is Better, but Only If You Have the Right Equipment
HDMI 2.1 is the new standard for the format, making it superior in every way to HDMI 2.0. As long as you have compatible devices, you’ll get a superior audio/video experience by making the cable switch. That said, HDMI 2.0 is still adequate for most people, especially if you don’t own a next-gen console or TV that supports 2.1. Just remember HDMI 2.1 is backward compatible, so it wouldn’t hurt to invest in some ultra-high-speed cables if you plan on investing in some new home cinema equipment over the next few years.
