CES 2019 marked the first time most of the world’s biggest TV makers introduced 8K TVs. And it’s good news that most will include the next-gen connection that will actually allow 8K TV shows, movies and games to get to those TVs.
LG, Sony, and Samsung all confirmed that their new 8K TVs will have HDMI 2.1 connections capable of the full 48-gigabit-per-second transfer speed necessary for the highest-bandwidth forms of 8K. LG added that its high-end 4K TVs will also support the standard, and Samsung’s 4K sets currently offer some HDMI 2.1 features.
You’ll eventually need new cables for those high-bandwidth 8K signals, when there are sources, which there currently aren’t — but we’ll discuss that in a moment. First, here’s a rundown of everything new we found out about HDMI 2.1 connection in 2019 and beyond, after talking with TV manufactures, an HDMI cable manufacturer and HDMI Licensing themselves at CES 2019.
What is HDMI 2.1 anyway?
HDMI 2.1 expands on the current HDMI 2.0 connection standard, a collection of features and capabilities that allows source devices (game consoles, streamers, Blu-ray players, etc.) to send audio and video to TVs.
For most people with current and even near-future 4K TVs, HDMI 2.1 isn’t a big deal, and HDMI 2.0 is plenty. It will handle 4K resolution at frame rates up to 60 per second, and even some varieties of 8K (24 and 30 fps). It also doesn’t require new HDMI cables.
But for the ultimate in futureproofing — or for people who buy an 8K TV — the full version of HDMI 2.1 is worth considering. It’s also potentially worthwhile for some gamers and people who want to use Dolby Atmos via eARC. Here’s what it offers.
- The physical connectors and cables the same as today’s HDMI.
- Improved bandwidth from 18Gbps (HDMI 2.0) to 48Gbps (HDMI 2.1).
- Can carry resolutions up to 10K, frame rates up to 120fps.
- New cables required for higher resolutions and/or frame rates.
- AV features include Dynamic HDR, ‘eARC’ (enhanced Audio Return Channel)
- Gaming features include VRR (variable refresh rate) and ALLM (auto low latency aka game mode)
Not all HDMI 2.1 is full HDMI 2.1
As we originally reported, HDMI Licensing is allowing companies to claim HDMI 2.1 compliance even if the TV can’t do all of 2.1’s features. So, for instance, a company with a TV that can do eARC and VRR, but not the 48Gbps required for 8K/60, could still say their TV is HDMI 2.1. They’re only allowed to do this if they also explain which specific features the TV supports, but if you’re thinking this will lead to confusion, so do we.
While it’s true a 4K TV doesn’t need 48Gbps, and that same TV could take advantage of eARC and VRR, this extra level of explanation, potentially requiring some more research on your part, isn’t intuitive and is potentially confusing.
We’ll discuss this more in the future for sure.
Be wary of ‘2.1 cables’
There’s no reason you should be looking for Ultra High Speed HDMI cables right now. Once called ’48G’ and already incorrectly labeled as ‘HDMI 2.1’ cables, they offer no benefit to your current 4K TV.
You can already find some of these cables for sale on the web. The specification has been available for several months, but there is, as yet, no compliance testing. Which is to say, HDMI Licensing can’t say if any of these cables are actually Ultra High Speed. It’s possible they are, but if you’ve never heard of the brand and they have no web presence, they almost certainly are not.
If you have your heart set on an 8K TV, the 2019 models won’t be shipping until later this year anyway, and perhaps by then we’ll have more info about what cables to look for. Even then, it might not be a concern because there’s nothing in 8K to watch.
No 8K sources yet
No one is talking, publicly at least, about 8K sources. Yet.
What 8K content that’s out there you’ll only be able to get via the web. YouTube, for instance, already has 8K videos but it’s unclear whether 8K TVs will actually be able to play it with their YouTube apps (we asked LG and they said they’d get back to us, while Samsung also hedged with its Q900). Whether you’ll have the Internet speed to stream 8K is a whole other aspect, but one best left for a different article.
There’s no talk about an 8K Blu-ray format, so really there’s only streaming. On some TVs you’ll be able to play content from a USB drive, but that doesn’t seem like it will be a common option to watch 8K content.
However, the Olympics are in Japan next year, and China in 2022, so it’s a safe bet we’ll see a way to get 8K to the TV via something external and box-shaped to coincide with those events. But I’d be surprised if we even get a glimpse of something like that before the end of this year.
Copper limitations, optical answers
I often use the analogy that bandwidth is like a pipe: big pipe, lots of water, small pipe, less water. 4K needs a big pipe. 8K needs a storm drain.
HDMI cables are actually multiple smaller wires all bundled together. A handful of spaghetti, if you will, all mashed together with rubber. To keep the overall cable diameter small, so it’s bendable and not impossible to use in your house, each of the strands inside has to be kept as small as possible. Other parts, like shielding, can shrink too, but all only to an extent.
The thinner these strands of copper are, the more signal gets lost over the length of the wire. Too thin, and you won’t get anything, or the cable won’t be able to transfer really high resolutions. Go the other way, and make all the parts thick, and it would be like trying to connect your TV and cable box with a garden hose, and not one of those fancy flexible ones either.
In talking with HDMI Licensing, and Ian Jackson from Silicon Line, there’s an expectation that it won’t be practical to do 48Gbps using traditional copper wires over longer lengths, even just a few meters. Looking at some of the cable prototypes at the show, the longer ones were exceptionally thick. Fine for some situations, certainly, but if you’re trying to run it around corners or tight spaces, it’s going to be a hassle.
However, this potential limitation might not be an issue. The price of optical HDMI cables has dropped significantly in recent years. Jackson has said new chip design allows his company to be similar in price, and possibly cheaper, than copper cables. They’ll also only be 3mm thick. Despite being optical, i.e. requiring a change from electrons to photons and back again, they likely wouldn’t need any external power. They’ll pull what juice they need from the HDMI connection itself.
Now that’s just one company, and it’s super-early in the HDMI 2.1 era. It’s also worth noting that in the early days of HDMI, many believed longer runs would always require super-thick cables too, and thanks to active cable tech, along with optical and other developments, reasonably thin cables are relatively inexpensive.
The optical technology does seem like it will become a more viable option for long Ultra High Speed cable runs, if the prices keep dropping. To give you an idea where we are now, Monoprice’s HDMI-over-optical cables cost about twice per-foot what the comparable active long-run copper HDMI cables do. That seems like a lot, until you consider the copper cables are very cheap. The optical cables are available in much greater distances too, it’s worth noting.
So while HDMI-over-optical isn’t new, its continuing reduction in price and potential for an even greater size difference compared to copper could be an interesting trend to keep an eye on as HDMI 2.1 rolls out.