What is HDMI 2.1 and should you need to worry about it?

HDMI Specification 2.1 or HDMI 2.1 is the most recent update of the HDMI specification (June 2021). The headline is that any source, display and everything in between must support HDMI 2.1 in order to take advantage of the higher video resolution support (8K up to 10K!) and faster refresh rates (4K up to 120fps and 8K at 60fps). If you have an older HDMI cable then it is unlikely that it will be able to handle the bandwidth that’s required for HDMI 2.1.

Do I need a 2.1 HDMI cable?

Answer

What do all those new HDMI acronyms mean?

• eARC: Enhanced Audio Return Channel
  An update to standard ARC support. eARC allows audio to be ‘pulled’ from a display and carried down the HDMI cable to an audio device like a Sonos soundbar or an AVR. The biggest difference between ARC and eARC is that eARC is capable of pulling uncompressed audio formats like 5.1, 7.1 and high bitrate, object based audio such as Dolby Atmos and DTS:X.
• VRR: Variable Refresh Rate
  VRR enables a gaming source such as a console or computer to deliver video frames as fast as it can, which in many cases is slower than the normal static refresh rate.
• ALLM: Auto Low Latency Mode
  This is a new HDMI feature that allows a source (e.g. an gaming console such as the XBox One S or XBox One X) to direct all compatible components in the HDMI chain (things like AVRs and displays) to enter its a low-latency mode automatically. This allows the picture to be displayed with the lowest possible delay which is important in gaming.
• QMS: Quick Media Switching
  Reduces the black screen you see when you change source. This works when resolutions are the same between HDMI connections.
• QFT: Quick Frame Transport
  Another measure to transport data from the source to the display as fast as possible.