In an interesting turn of events this week, the VESA has announced that work has begun on the next generation DisplayPort standard. Citing the need for even greater amounts of display bandwidth, the standards association has stated that they’re looking to double the bandwidth available versus the current HBR3 signaling standard. The goal is to publish the standards update in the next 18 months, which would put an announcement in a 2019 timeframe with hardware in 2020 or beyond.

The DisplayPort standard was most recently updated in the middle of 2016, with the release of DisplayPort 1.4. However DP 1.4 was itself only a minor feature update of the standard; it continued to use the High Bit Rate 3 (HBR3) physical signaling standard, which was released with DisplayPort 1.3 in 2014. As a result, it’s actually been a few years now since the underlying signaling standard has been updated.

With HBR3, DisplayPort 1.3/1.4 can offer up to 32.4 Gbps of raw bandwidth in a 4 lane configuration. This is enough for a 5120x2880 monitor at 60Hz with full RGB color, or various 8K configurations with either Display Stream Compression or lesser chroma subsampling. This is sufficient for the moment, but as the VESA plainly notes, their member manufacturers will need higher bandwidth standards for monitors over 8K resolutions, higher resolution AR/VR setups, and for that matter 8K setups without any form of compression. Compounding matters competitively, the HDMI consortium is already in the middle of launching the HDMI 2.1 standard, complete with its higher bandwidth 48 Gbps cable.

Consequently, the VESA has begun work on a new version of DisplayPort, complete with a faster signaling standard. This presumably will be HBR4, and with the VESA’s current guidance of doubling (or more) HBR3’s speeds, this would mean a cable that can offer 64.8 Gbps or better of bandwidth. Which if that sounds like a lot of bandwidth, it is: that’s 81% of the cable bandwidth of a Thunderbolt 3 cable, which requires active signaling. So the VESA’s bandwidth goals are going to be quite aggressive here, especially if they’re continuing to aim for a passive cable.

DisplayPort Signaling Standards
Standard Raw Bandwidth
(4 Lanes)
Target Monitor Resolutions
HBR1 (DP 1.0/1.1) 10.8 Gbps 1440p@60Hz
HBR2 (DP 1.2) 21.6 Gbps 4K@60Hz
HBR3 (DP 1.3/1.4) 32.4 Gbps 4K@120Hz &
8K@60Hz (w/DSC)
HBR4? 64.8 Gbps+ >8K@60Hz &
More HDR Configurations

Meanwhile as a side benefit of a higher speed signaling standard, this will allow device vendors to improve the amount of bandwidth available via USB-C ports that offer DisplayPort Alt Mode. Currently USB-C can carry from 1 to 4 lanes of DisplayPort, with the most common configuration being 2 lanes of DP to leave a spare pair for USB 3.x data. The flip side of this is that in this 2 lane configuration, DisplayPort 1.3/1.4 can only offer enough bandwidth to do 4K@60Hz without compression, so there’s a more immediate desire to boost bandwidth here for laptops and other devices.

On a final note, what’s interesting is that in the VESA’s brief announcement, nothing is being said about their plans for cabling or ports. With USB-C’s DisplayPort Alt Mode, the need for a dedicated DisplayPort and cabling has decreased. And at the same time the industry as a whole is gravitating towards reusing USB-C ports and cables for all high bandwidth I/O needs. So it will be interesting to see whether the VESA keeps their own port and cabling for the next DisplayPort standard, or whether it becomes purely a new signaling standard for DisplayPort Alt Mode.

Source: VESA

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  • Lolimaster - Friday, January 05, 2018 - link

    When old fashioned business stops the better good.

    HDMI needs to die.
    Reply
  • Lord of the Bored - Saturday, January 06, 2018 - link

    You ain't lyin'. DP is such a NICE standard, and it's being overlooked in favor of a hacky upgrade of DVI, which was a hacky digital interface to start. A hacky update that costs money to implement despite being blatantly inferior to the free standard. Reply
  • alexvoda - Saturday, January 06, 2018 - link

    AFAIK HDMI does have one technical advantage over DisplayPort: longer cable lengths. Reply
  • Kevin G - Saturday, January 06, 2018 - link

    Not true since DP supports active cabling in the specification. Host power is guaranteed for various in-line amplifiers, media conversion (fiber) and active conversion to different displays standards.

    The various fiber HDMI solutions that embedded a fiber transmitter/receiver take power off of the HDMI hot plug pin which is not guaranteed to provide enough current to drive the transmitter/receiver. I've had plenty of devices simply not work with those cables because of that. Which makes sense as these do not fall into the HDMI spec.
    Reply
  • nfriedly - Friday, January 05, 2018 - link

    Ehy are there practically no monitors out there that support DP 1.3/1.4 or > 4k resolution?

    Even the LG 5k ultrafine monitor ends up using DP1.2 @ 4k when connected to anything besides macOS :(
    Reply
  • nfriedly - Friday, January 05, 2018 - link

    Why* Reply
  • Kevin G - Saturday, January 06, 2018 - link

    The LG 5K Ultrafine displays uses TB3 to send the video signal as two independent DP 1.2 streams (2560 x 2800). A PC with TB3 should be able to drive this at full resolution but it requires drivers to do so since its is TB3 device. This also requires that the PC manufacturer to have connected two DP 1.2 ports into the TB3 controller (several have only connected one). I was able to hook up a Dell 5510m to this displays at a trade show prior to wide release in 2016 and just got TB errors and no picture.

    Internally, this monitor acts as if it is a two cable solution due to the two DP 1.2 streams being encapsulated. The timing issues prior two cable solutions are resolved due the demux of both streams sharing a common sync.

    To make matters more fun, Intel's new TB3 controllers just announced will encapsulate a single DB1.3/1.4 stream. For monitor makers, they'll still need to support the more complex dual DP 1.2 stream to maintain backwards compatibility with prior TB3 controllers.
    Reply
  • DanNeely - Friday, January 05, 2018 - link

    DP1.4 GPU support only became available last year. Prior to then 5k60 needed 2xdisplayport cables or the equivalent. Presumably whatever Apple's doing to get 5k over a single TB3 cable (native support is limited to 4k60, presumably they're sending part of the video signal as part of the general data payload) lacks driver support on Windows/Linux.

    The lack of good cabling support (2x cable got a really bad reputation due to buggy implementations when the 1st 4k displays came out) until recently has probably been a major factor in holding back any manufacturer interest in 5k displays. Now I suspect the main limiting factor is the display makers seeing a bigger potential market in 4k 120/144 displays and putting their initial efforts there instead. That's mostly an assumption on my part, AUO has been trying to get a 4k 144 panel to production since 2017Q2 (although I suspect the 384 zone HDR part is the problem), no other panel maker has talked about new 4k120/144 or 5k60 displays anywhere that the maintainer of TFTCentral's panel DB has seen.
    Reply
  • r3loaded - Friday, January 05, 2018 - link

    The monitors will come, the cable standard needs to be in place first. 64.8 Gbps is plenty to do 4K@144Hz with 12-bit colour, 5K@120Hz with 12-bit, or 5K@144Hz with 10-bit. None of these are possible with DP1.4, and even HDMI 2.1 can only handle the first one. Reply
  • Pinn - Friday, January 05, 2018 - link

    tldr, can it use usb-C on both ends? Reply

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