DisplayPort 2.1b Arriving This Spring With DP80LL Cables

[phoronix]

Phoronix: DisplayPort 2.1b Arriving This Spring With DP80LL Cables

In addition to the HDMI Forum announcing the HDMI 2.2 specification for release in the first half of this year, VESA also took to CES 2025 to announce their forthcoming DisplayPort 2.1b standard...

https://www.phoronix.com/news/DisplayPort-2.1b-Coming

[risho]

What are the resolution/refresh rate limits of displayport 2.1b with and without dsc?

[bemerk]

Where are the attempts to have something like CEC&ARC in the DP spec so we can finally move to a common standard for tvs and computers?

[cl333r]

Where are the attempts to have something like CEC&ARC in the DP spec so we can finally move to a common standard for tvs and computers?

I was actually surprised recently that from the cheap monitors all were HDMI, none DP, while looking for an HDR TV as monitor. Now I see why.

[Britoid]

Where are the attempts to have something like CEC&ARC in the DP spec so we can finally move to a common standard for tvs and computers?

In one universe there's a world where TVs use the superior display port, unfortunately it's not this one.

I wouldn't be shocked if the HDMI group has some licensing terms with OEMs that prevent them using display port on televisions.

[KoenDG]

Wasn't the whole thing with 2.1a that it wasn't a requirement to implement the entire spec? That you could call yourself "2.1a" if you implemented even a single feature and none of the rest?

Or am I misremembering?

Wonder if it's gonna be the same thing?

[bemerk]

I wouldn't be shocked if the HDMI group has some licensing terms with OEMs that prevent them using display port on televisions.

Still DP could at least offer the same features and be the superior spec so we can mock the TV and HomeCinema producers

[skeevy420]

What are the resolution/refresh rate limits of displayport 2.1b with and without dsc?

What are the important features of DisplayPort 2.1?

• DisplayPort 2.1 enables up to 3X increase in video bandwidth performance (max payload of 77.37 Gbps)
  • Maximum link rate to up to 20 Gbps/lane and features more efficient 128b/132b channel coding, delivering a maximum payload of 77.37 Gbps
  • First standard to support 8K resolution (7680 x 4320) at 60 Hz refresh rate with full-color 4:4:4 resolution, including with 30 bits per pixel (bpp) for HDR-10 support
• Beyond 8K resolutions: Example Configurations:
  • Single display resolutionsOne 16K (15360×8460) display 60Hz and 30 bpp 4:4:4 HDR (with DSC)
    One 10K (10240×4320) display 60Hz and 24 bpp 4:4:4 (no compression)
  • Dual display resolutionsTwo 8K (7680×4320) displays @120Hz and 30 bpp 4:4:4 HDR (with DSC)
    Two 4K (3840×2160) displays 144Hz and 24 bpp 4:4:4 (no compression)
  • Triple display resolutionsThree 10K (10240×4320) displays 60Hz and 30 bpp 4:4:4 HDR (with DSC)
    Three 4K (3840×2160) displays @90Hz and 30 bpp 4:4:4 HDR (no compression)
  • When using only two lanes on the USB-C connector via DP Alt Mode to allow for simultaneous SuperSpeed USB data and video, DP 2.0 can enable such configurations as:Three 4K (3840×2160) displays 144Hz and 30 bpp 4:4:4 HDR (with DSC)
    Two 4Kx4K (4096×4096) displays (for AR/VR headsets) @120Hz and 30 bpp 4:4:4 HDR (with DSC)
    Three QHD (2560×1440) @120Hz and 24 bpp 4:4:4 (no compression)
    One 8K (7680×4320) display @30Hz and 30 bpp 4:4:4 HDR (no compression)

They talk about 4K600 and 8K120 on their main page.

[caligula]

Where are the attempts to have something like CEC&ARC in the DP spec so we can finally move to a common standard for tvs and computers?

Both are pretty crappy. Ever tried programming CEC with some pulse eight adapter / rpi? It's slow as hell. Probably fully synchronous. E.g. starting an AV receiver + TV takes something like 15 seconds here. Same for shutdown sequence. My receiver or TV only supports stereo and compressed 5.1 via HDMI ARC.

[Old Grouch]

What are the important features of DisplayPort 2.1?

• DisplayPort 2.1 enables up to 3X increase in video bandwidth performance (max payload of 77.37 Gbps)
  • Maximum link rate to up to 20 Gbps/lane and features more efficient 128b/132b channel coding, delivering a maximum payload of 77.37 Gbps
  • First standard to support 8K resolution (7680 x 4320) at 60 Hz refresh rate with full-color 4:4:4 resolution, including with 30 bits per pixel (bpp) for HDR-10 support
• Beyond 8K resolutions: Example Configurations:
  • Single display resolutionsOne 16K (15360×8460) display 60Hz and 30 bpp 4:4:4 HDR (with DSC)
    One 10K (10240×4320) display 60Hz and 24 bpp 4:4:4 (no compression)
  • Dual display resolutionsTwo 8K (7680×4320) displays @120Hz and 30 bpp 4:4:4 HDR (with DSC)
    Two 4K (3840×2160) displays 144Hz and 24 bpp 4:4:4 (no compression)
  • Triple display resolutionsThree 10K (10240×4320) displays 60Hz and 30 bpp 4:4:4 HDR (with DSC)
    Three 4K (3840×2160) displays @90Hz and 30 bpp 4:4:4 HDR (no compression)
  • When using only two lanes on the USB-C connector via DP Alt Mode to allow for simultaneous SuperSpeed USB data and video, DP 2.0 can enable such configurations as:Three 4K (3840×2160) displays 144Hz and 30 bpp 4:4:4 HDR (with DSC)
    Two 4Kx4K (4096×4096) displays (for AR/VR headsets) @120Hz and 30 bpp 4:4:4 HDR (with DSC)
    Three QHD (2560×1440) @120Hz and 24 bpp 4:4:4 (no compression)
    One 8K (7680×4320) display @30Hz and 30 bpp 4:4:4 HDR (no compression)

They talk about 4K600 and 8K120 on their main page.

As far as television is concerned, improving the resolution is less important than improving the frame rate. The limit of the acuity of the human eye has (effectively) been reached: the limit of the human visual system to perceive problems with the display of moving objects (both high-speed linear, and rotational) has not been reached.

To quote: NABAmplify: Your Eyes vs. Frame Rates: What You Can (and Can’t) See

““In order to appear perfectly smooth and eliminate all stutter, each frame must move the image by no more than the smallest Angular change humans can perceive.
Say you’re sitting in a movie theater near the front of the middle of the hall. So, the screen occupies 55 degrees of your field of view. If you had a small dot that travelled from one side of the screen to the other, you would need 3300 frames-per-second to make that dot appear to move perfectly smooth across the screen in one second, as 55 degrees divided by 1/60th of a degree. If you want to move it in half a second [perfectly smoothly], you’d have to double that to 6,600 frames-per-second.” There is no theoretical upper limit, he says, but he suggests that 20,000 frames-per-second would cover almost all possible scenarios.

The human visual system does not have a 'frame rate' as such - it does not work like a digital video camera, or a traditional film camera with a 25 fps shutter, but it is sensitive to the discrepancies between projecting an image of moving objects at a certain frame rate and 'smooth' reality. Increasing the display frame rate reduces those discrepencies, but as the example shows, artificially contrived (pathological) situations can be generated that expose the limitations of frame-based displays.

Note that this is not related to the lower limit of about 10 frames per second needed for images to generate perceived 'apparent motion'.