from the top-interfacers dept.
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.
Previously: HDMI 2.1 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!
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
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.