Another HDMI 2.1 benefit for gamers, QFT technology reduces, though doesn’t eliminate, what is called "input lag": the brief delay between your input on a control pad or keyboard and something happening in-game. QFT shortens the delay sending active video across the HDMI cable. This technology is just beginning to make an appearance in HDMI 2.1 devices. Auto Low Latency Mode (ALLM)

This is what allows it to support 8K video at 60fps and 4K video at 60-120fps (depending on the game you're playing). Hmmm. I have an LG 4K G1 series UHDTV. It's connected to a pair of KEF LS60 speakers (and KEF KUBE 10b subwoofer) via an HDMI eARC cable.

According to HDMI.org, if you currently use a standard HDMI cable with Ethernet, or a High-Speed HDMI cable with Ethernet, you should be fine. Ultra High-Speed HDMI cables with Ethernet will definitely work. Full HD TVs and monitors, depending on their refresh rate, will be able to play games in 60fps or 120fps. These cables tend to be a bit pricier than those that support HDMI 2.0 or lower, but that, unfortunately, comes with having the latest and greatest tech.

Active: An active HDMI cable has a small chip built into the cable that takes a little power from the device's HDMI connector and uses it to boost the HDMI signal. These cables cost a little extra, but are far more likely to work. A long passive cable might work for you, but it might not. It depends on your gear. Since they're not significantly more expensive, they're worth considering for any long run. The latest version of HDMI is called 2.1. This is a huge leap forward in terms of bandwidth, capable of up to 8K resolutions and beyond. There are also new cables, called Ultra High Speed, and these can carry 8K signals as well as the popular 4K/120Hz used by the Xbox Series X and others. If you're into gaming, it's worth trading up to one of these, and as we found with the Cable Matters cords above, it doesn't incur much of a price premium. The only other "fail" mode of HDMI cables is sparkles. This looks like snow on the screen. It can be heavy enough to look like static, like an old TV tuned to a dead channel, or it can be random-but-regular flashes of white pixels. This means you'll need new cables. Of course, what counts are the specs. This HDMI 2.1 cable comes with 8K output at up to 120Hz, granting compatibility with some of the most cutting-edge displays on the market. It also includes 4:4:4 RGB HDR, Dolby Vision, and 12-bit color.In broad strokes, the build and material quality is much more important in a long HDMI cable than short. Over 15 feet there is a much higher chance that a mediocre cable won't work, or won't work at the resolution you want. This still doesn't mean you need to spend a fortune on a long cable, there are plenty of options for roughly the same price per-foot as the ones mentioned above. It does mean that no-name cables might be less likely to work. LG was the first manufacturer to go all-in with the new standard, producing the first 4K TVs to sport HDMI 2.1 ports in 2019. All LG's 2022 and 2023 OLED TVs have up to four HDMI 2.1 ports, with Samsung offering one on most models and four on its flagship sets. Meanwhile, much of Panasonic and Sony's 2022 and 2023 ranges also sport a mixture of ports. You can think of bandwidth like a pipe. You need to be able to get a lot of "water" through the pipe with 4K and HDR content. A high speed cable needs to be "big" enough to handle it all. The good thing is, if it works, it works. For example, if you're sending a 4K HDR signal from your 4K Blu-ray player to your 4K HDR TV and the TV shows a 4K HDR signal, you're set. It's not possible to get a better image using a different 4K HDMI cable. That's not how the technology works. It is important to note that while the new consoles use HDMI 2.1 as the connection, it doesn't mean your TV also needs to support HDMI 2.1.