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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  • DanNeely - Friday, January 05, 2018 - link

    Last paragraph: "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." Reply
  • Dark_Complex - Friday, January 05, 2018 - link

    "this would mean a cable that can offer 64.8 Gbps or better of bandwidth"

    Are you sure that VESA is talking about doubling the raw bandwidth and not the usable bandwidth? It would seem sensible for them to move to a more efficient encoding at this point like USB, PCIe and Ethernet have done.
    Reply
  • extide - Saturday, January 06, 2018 - link

    Wow, I am shocked that they are still using 8b/10b encoding (had to look that up). Yeah, I wouldn't be surprised to see them move to something like 128b/130b in the next rev... it would be silly not to. Reply
  • Ryan Smith - Saturday, January 06, 2018 - link

    The VESA has historically quoted raw bandwidth rather than effective bandwidth. But right now they aren't saying anything more than "twice the bandwidth", so a reduction in overhead is definitely not off the table. Reply
  • ummduh - Friday, January 05, 2018 - link

    Meanwhile in the real world, I literally couldn't find a single DP monitor to buy locally in a rather large city. Not a single one of any size. Reply
  • linuxgeex - Saturday, January 06, 2018 - link

    What I'd really like is an 80" curved 8192x3072 display. Hopefully that's doable in the next 2 years.

    Please, nobody suggest 3 4k projectors.
    Reply
  • Kevin G - Saturday, January 06, 2018 - link

    If you want 8192 x 3072 resolution today and the 2.67:1 aspect ratio, you could do it today using LED tiles at 256 x 256 base resolution. Just don't ask about the price or how large it'll be. Reply
  • Mumrik - Saturday, January 06, 2018 - link

    A quick search on a national (Denmark) PC parts price checker gave me 867 monitors with displayport support and 1102 with HDMI. It should be easy to find. Reply
  • pixelstuff - Saturday, January 06, 2018 - link

    Now if we could just get the TV/Blu-ray device manufacturers to put these on all their devices. Reply

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