The High-Definition Multimedia Interface 2.1 specification has been released. The total transmission bandwidth has been increased to 48 Gb/s from the 18 Gb/s of HDMI 2.0 (or a maximum data rate of 42.6̅ Gb/s from 14.4 Gb/s). The new data rate is effectively tripled to 128 Gb/s when using Display Stream Compression (DSC).
Using DSC, HDMI 2.1 cables can transmit 4K (3840×2160) @ 240 Hz, and 8K (7680×4320) as well as UW10K (10240×4320) at 120 Hz. Without DSC, you will be able to transmit 4K @ 120 Hz, 5K (5120×2880) @ 120 Hz, 8K @ 60 Hz, and UW10K @ 30 Hz. Keep in mind that color depth and chroma subsampling also affect the necessary data rate.
The specification also adds new features such as dynamic high-dynamic-range support (you read that right - the first "dynamic" refers to "dynamic metadata that allows for changes on a scene-by-scene or frame-by-frame basis"), Variable Refresh Rate, Quick Frame Transport, Quick Media Switching, and Auto Low-Latency Mode:
This new version of the HDMI specification also introduces an enhanced refresh rate that gamers will appreciate. VRR, or Variable Refresh Rate, reduces, or in some cases eliminates, lag for smoother gameplay, while Quick Frame Transport (QFT) reduces latency. Quick Media Switching, or QMS, reduces the amount of blank-screen wait time while switching media. HDMI 2.1 also includes Auto Low Latency Mode (ALLM), which automatically sets the ideal latency for the smoothest viewing experience.
- Here is the HDMI Forum's PPT PDF explaining HDMI 2.1.
- Here are the data rates and cables required for various resolutions/bit depths/chroma. Resolutions requiring Display Stream Compression are indicated.
- Here is another table showing the various color depths and chroma subsampling levels.
Also at the HDMI Forum, AnandTech, Tom's Hardware, and The Verge.
Previously: HDMI 2.1 Announced
Related Stories
The key specifications for the HDMI 2.1 standard have been announced:
The HDMI Forum on Wednesday announced key specifications of the HDMI 2.1 standard, which will be published in the second quarter. The new standard will increase link bandwidth to 48 Gbps and will enable support for up to 10K resolutions without compression, new color spaces with up to 16 bits per component, dynamic HDR, variable refresh rates for gaming applications as well as new audio formats
The most important feature that the HDMI 2.1 specification brings is massively increased bandwidth over predecessors. That additional bandwidth (48 Gbps over 18 Gbps, a bit more than what a USB-C cable is rated for) will enable longer-term evolution of displays and TVs, but will require the industry to adopt the new 48G cable, which will keep using the existing connectors (Type A, C and D) and will retain backwards compatibility with existing equipment (which probably means 8b/10b encoding and effective bandwidth of around 38 Gbps). The standard-length 48G cables (up to two meters) will use copper wires, but it remains to be seen what happens to long cables. It is noteworthy that while some of the new features that the HDMI 2.1 spec brings to the table require the new cable, others do not. As a result, some of the new features might be supported on some devices, whereas others might be not.
The increased bandwidth of HDMI 2.1's 48G cables will enable support of new UHD resolutions, including 4Kp120, 8Kp100/120, 10Kp100/120, and increased frame rates. It is no less important that increased bandwidth will enable support of the latest and upcoming color spaces, such as BT.2020 (Rec. 2020) with 10, 12, or even more advanced with 16 bits per color component and without compression. HDMI Forum does not say it explicitly, but the version 2.1 of their standard will also likely support the BT.2100 (Rec. 2100), which has a number of important enhancements to the BT.2020 when it comes to HDR. While HDMI 2.0 already supports BT.2020 and HDMI 2.0b adds support for HDR10 (through support for Hybrid Log-Gamma (HLG)), it only can transmit 10 and 12 bits per sample at 4Kp60 resolution. To support HDR at 8K, one will need HDMI 2.1.
10K resolution (5760p)? 16-bits per channel color (281,474,976,710,656 shades of grey)? It's necessary!
More 8K (4320p) TVs will be coming soon. AU Optronics has announced plans to ship 8K panels to TV manufacturers starting in the first half of 2018:
The lineup of panels featuring a 7680×4320 resolution will be aimed at ultra-high-end TVs and sizes will range from 65 to 85 inches, said Liao Wei-Lun, president of AUO's video products business group, at a press conference. The high-ranking executive did not disclose other specifications of the panels, such as luminance and contrast ratio, but given their positioning, it is logical to expect their characteristics to be comparable to 8K UHDTVs to be offered by LG and Samsung.
Multiple TV makers demonstrated various 8K UHDTVs at various trade shows in the recent years, but so far no one has started to sell them. Given the lack of content, it is hard to expect high demand for 8K televisions in the next couple of years, aside from the halo factor - nonetheless, AUO expects 8K panels to account for 10% of its '65-inch and above' panel shipments in 2020. The presumably high-cost of the panels would indicate that in terms of unit shipments this might still be a low-ish number. However, as with 4K displays, someone has to release 8K TVs to stimulate content providers to offer appropriate material. At this year's CES, Samsung demonstrated its Q9S, its first commercial 8K TV-set, but it did not announce its pricing or availability timeframe. LG and Sony also demonstrated their 8K TVs at CES 2018, but nothing is clear about their plans regarding these products.
[...] As for 8K displays for PCs, Dell is currently the only company to offer an 8K monitor (this one is based on a panel from LG, so the latter might introduce its own 8K display at some point). Philips last year promised to start shipments 328P8K monitor in 2018, so expect the product to hit the market in the coming months too.
Need something to watch on your 8K TV? How about the 2020 Olympics?
Also at DigiTimes.
Related: LG to Demo an 8K Resolution TV at the Consumer Electronics Show
Dell Announces First "Mass-Market" 8K Display
Philips Demos an 8K Monitor
Pimax Launches Kickstarter for "8K" Virtual Reality Headset
HDMI 2.1 Released
LG's 88-inch 8K OLED TV
VESA Announces DisplayPort 2.0 Standard: Bandwidth For 8K Monitors & Beyond
While display interface standards are slow to move, at the same time their movement is inexorable: monitor resolutions continue to increase, as do refresh rates and color depths, requiring more and more bandwidth to carry signals for the next generation of monitors. Keeping pace with the demand for bandwidth, the DisplayPort standard, the cornerstone of PC display standards, has now been through several revisions since it was first launched over a decade ago. And now this morning the standard is taking its biggest leap yet with the release of the DisplayPort 2.0 specification. Set to offer nearly triple the available bandwidth of DisplayPort 1.4, the new revision of DisplayPort is almost moving a number of previously optional features into the core standard, creating what's in many ways a new baseline for the interface.
The big news here, of course, is raw bandwidth. The current versions of DisplayPort – 1.3 & 1.4 – offer up to 32.4 Gbps of bandwidth – or 25.9 Gbps after overhead – which is enough for a standard 16.7 million color (24-bit) monitor at up to 120Hz, or up to 98Hz for 1 billion+ (30-bit) monitors. This is a lot of bandwidth, but it still isn't enough for the coming generation of monitors, including the likes of Apple's new 6K Pro Display XDR monitor, and of course, 8K monitors. As a result, the need for more display interface bandwidth continues to grow, with these next-generation monitors set to be the tipping point. And all of this is something that the rival HDMI Forum has already prepared for with their own HDMI 2.1 standard.
DisplayPort 2.0, in turn, is shooting for 8K and above. Introducing not just one but a few different bitrate modes, the fastest mode in DisplayPort 2.0 will top out at 80 Gbps of raw bandwidth, about 2.5 times that of DisplayPort 1.3/1.4. Layered on that, DisplayPort 2.0 also introduces a more efficient coding scheme, resulting in much less coding overhead. As a result, the effective bandwidth of the new standard will peak at 77.4 Gbps, with at 2.98x the bandwidth of the previous standard is just a hair under a full trebling of available bandwidth.
Related: HDMI 2.1 Announced
Linux, Meet DisplayPort
HDMI 2.1 Released
VirtualLink Consortium Announces USB Type-C Specification for VR Headsets
(Score: 4, Interesting) by jmorris on Wednesday November 29 2017, @09:08PM (2 children)
Short version, this is why they are dumping "Ultra Def" TVs everywhere. Because none of them are. Now we finally have a connector and cable that can deliver the promise of UHD, 2160p60@12bit formatted as RGB so in another year or two we will see affordable gear implementing it. Everything out there now was placeholders. Some can play UHD BD and the internal streaming services might be able to talk to the display fast enough but it is streaming quality so not even as good as the UHD BD. But soon we will have displays we can connect to PCs that can fully implement UHD workflows at full quality.
Which is nice and all but they already want everyone to consider UHD an already obsolete stopgap and begin lusting after 4K and 8K even though this new spec can't deliver on those.
(Score: 2) by takyon on Thursday November 30 2017, @03:42AM (1 child)
UHD or UHD BD = 3840x2160.
This cable can deliver on 8K. 8K at 60 Hz without DSC, or 8K at 120 Hz with DSC.
Previous 18 Gbps HDMI cable ("Premium") could deliver 2160p60@8bit formatted as RGB. 10-bit color adoption is still ongoing and I haven't seen much 12-bit since HDR is still very new. Even if chroma subsampling was needed on the TV, it was probably good enough.
Samsung added a superMHL [wikipedia.org] connector to some of its 8K TVs [valleyhometheater.com].
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
(Score: 2) by jmorris on Thursday November 30 2017, @04:50AM
Nope, read it again. 4:2:0 is utterly unsuitable for PC work, only TV. Horrible color fringes, especially with text, unless you strictly stick to black and white. So the other choice is compressed, which may or may not be suitable for PC work, we will need to wait until this stuff moves from theory to product we can look at. And to achieve 120hz you need to both butcher the color and compress what is left. Again, you might be able to play movies on that but forget a desktop for content creation. HDMI 2.1 finally gets us to the all of the promised UHD modes but will need another spec bump to go beyond. Even 5K requires compression or dropping 120Hz or HDR. It is a crapload of bits to move at consumer electronics hardware quality.
(Score: 3, Insightful) by DannyB on Wednesday November 29 2017, @10:57PM (4 children)
HDMI still has no locking connector.
Doesn't the HDMI forum understand how important it is to create a new incompatible connector so that millions of adapters can be sold?
The lower I set my standards the more accomplishments I have.
(Score: 1) by Ethanol-fueled on Wednesday November 29 2017, @11:05PM (3 children)
Why is that a big deal? Seriously, the mechanism of "locking connector" is obvious but why add the additional complexity?
Tripping over cables is a thing of the past unless you're white trash like me running extension cords and audio cables under your living room rug.
(Score: 0) by Anonymous Coward on Thursday November 30 2017, @04:49AM
I think you and others are missing the fact that comment was meant as a joke. Just look at the part about requiring people to buy adapters.
(Score: 2) by DannyB on Thursday November 30 2017, @02:37PM (1 child)
It was meant to be Funny not Inciteful.
I don't think tripping over cables will ever completely disappear. Which brings up another good reason to have locking connectors. When you trip over cables, and it does happen, even if less frequently; tripping over the cable has a non-zero probability of causing other equipment damage -- and thus additional sales. It's good for corporations. Therefore it is objectively good for everyone.
The lower I set my standards the more accomplishments I have.
(Score: 0) by Anonymous Coward on Thursday November 30 2017, @05:24PM
I bought a bunch of cheap magnetic breakaway cables off of Amazon. They are great for accidental trips, or being around the kids, or when I'm at work or home and need to leave for an appointment. Just close the lid and walk away an I don't have to suffer the fact that you cannot ever seem to plug USB in correct way the first or second time.
(Score: 0) by Anonymous Coward on Thursday November 30 2017, @02:30AM (1 child)
(Score: 0) by Anonymous Coward on Thursday November 30 2017, @02:53AM
Tennyson may apply here?
Theirs not to make reply,
Theirs not to reason why,
Theirs but to do and die.
Understanding HDMI is well above my pay grade.
(Score: 4, Funny) by crafoo on Thursday November 30 2017, @03:47AM (3 children)
I feel like an old man, but sometimes I plug this stuff in and nothing shows up on the screen. At least with component or even VGA I knew something would make it through. Also, sometimes it seems like the order in which I turn things on matter. I know this can't be true though because that would be insane.
(Score: 3, Funny) by takyon on Thursday November 30 2017, @04:05AM
Did you try unplugging and plugging it in again?
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(Score: 3, Insightful) by Knowledge Troll on Thursday November 30 2017, @04:32AM
Welcome to bugs - they will make you question your sanity.
(Score: 5, Interesting) by jmorris on Thursday November 30 2017, @05:01AM
Yea ordering can matter. And it sometimes takes a long time for all of the DRM to lock in. I put in a BD movie and it blanks several times as the menu is coming up. Hit play and it goes through the cycle again, lights blinking on the amp, the TV blinking the new connection notification, etc. It isn't mode switching since I locked the player to always output 1080p60 and it still does it. It is wretched. And it is utterly pointless since I have an HDCP stripping HDMI splitter I could put in that line if I wanted to have to buy another one for the place where it is now. HDCP is totally broken. Of course with UHD and HDMI 2.1 they will be trying again. Once more, with feeling!
Then there is the BS where I put a music disc in the BD player, turn on the amp and it, no matter what I disable, insists on finding a way to force the TV to power up. Wanna bet the player is wanting to negotiate HDCP or some such bull crap reason?
(Score: 4, Funny) by Anonymous Coward on Thursday November 30 2017, @04:52AM
Video used to be much simpler when it was analogue. It was all SECAM, PAL, NTSC or 576i.
If it was SECAM, it was D-SECAM, MESECAM or French SECAM, depending on where you were.
If it was PAL, it was PAL-M, which was like NTSC; PAL-N, which was like NTSC and like PAL-M; PAL-I; PAL-B/G or PAL-60, another one that is like NTSC.
And if it was NTSC, it was always NTSC-M, except when it was NTSC-J; NTSC-N, also known as NTSC50; PAL-M, which was like PAL but also like NTSC; or PAL-N, which was also like both PAL and NTSC.