There are numerous HDMI versions available on 2017 TVs, receivers and other gear. Here’s what you need to know about HDMI 2.0, 2.0a, 2.0b and 2.1.
Behind the version numbers
If you’re shopping for any product with HDMI in 2017, you should make sure it has at least HDMI 2.0. This gets you 4K resolution and frame rates of at least 60. More importantly, it gets you HDCP 2.2, the copy-protection protocol, so you can actually watch 4K content sent from an external device (like a Roku or 4K Blu-ray player).
What’s more, every piece in your AV chain needs HDMI 2.0/HDCP 2.2 for it to work. So if you have an HDMI 2.0 4K player and an HDMI 2.0 TV, but an older HDMI 1.4 soundbar or AV receiver in between… you’re out of luck.
Version 2.0a was a small update, adding support for high dynamic range (HDR)
Most of “b” is a carryover from “a” and “_” versions of 2.0, with some refinements, most notably Hybrid Log Gamma (HLG). This is a different way to transmit HDR content. For a deep dive, one of the co-creators is the BBC and it’s got a well-written PDF Q&A.
For now, though, don’t worry about it. There’s not much support for HLG yet. The only reason 2.0b is worth mentioning is it’s being implemented on 2017 TVs instead of HDMI 2.1.
What version for me?
The question becomes: Can a product can be upgraded, via a firmware update, to become “a”, “b”, or “.1″? The answer is: maybe, maybe and probably not. HDMI Forum, the people behind the HDMI standards, are understandably reluctant to discuss what manufacturers are able to do. We can figure a few things though.
Most HDR-compatible devices will have likely shipped from the factory with 2.0a. Since HDR is something that requires serious hardware, there’s no point in adding the ability to read HDR data in a TV that isn’t HDR. So the only products that could need 2.0a but didn’t ship with it are slightly older (around 2 years) source devices. Is it theoretically possible to add it? Yes. Likely? Probably not. Companies don’t love updating old gear with new features.
And of course, all the versions are backward-compatible, so you can connect your HDMI 1.4 Blu-ray player to your HDMI 2.0b TV and you shouldn’t have any issues.
“Shouldn’t” being the key word — but then, that’s HDMI.