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Comment by neverminder | Hacker News Reader

What really blew me away is that they went straight for Displayport 1.4 (https://en.wikipedia.org/wiki/DisplayPort#1.4) that was only announced on 1st of March 2016. DP 1.3 was approved on 15th of September 2014 and as of today there are no cards supporting it except this one (with backwards compatibility).

The bad news is that there's no news about new gen displays that could take advantage of this graphic card. I'm talking about 4K 120Hz HDR (https://en.wikipedia.org/wiki/High-dynamic-range_rendering) displays. This is a total WTF - we have a graphic card with DP 1.4 and we don't even have a single display with so much as DP 1.3...

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IMO still a preferable situation than what we had before - which was displays coming out with hacked up interfaces because they needed more bandwidth than there were video cards capable of driving it.

Displays get to play catchup for a while. This is great - it means we can avoid stupid hacks like MST.

Well, chicken and egg problem

It would also be useless to have the displays first and cards later

I guess some manufacturers have it lined up already

Well, that's understandable, however comments like this are really discouraging: "Proper HDR support for monitors is years away. Some budget trash with HDR will be released, but they won't come close to matching the HDR standard and will have tons of issues." (https://www.reddit.com/r/Monitors/comments/4hj4xv/what_are_s...)

There are monitors with 10 bit color depth, what exactly are you hoping to get beyond that?

10 bit is not the same as HDR and vice versa - http://www.dpreview.com/forums/thread/3822463

I think this article (from 2005!) is still quite good introduction to HDR: http://www.bit-tech.net/hardware/2005/10/04/brightside_hdr_e...

Your link is now bit outdated in the regard that these days there are plenty of consumer HDR standards/names out there. HDR10 and Dolby Vision are the two main competing standards, and we have marketing terms like "Ultra HD Premium" or "HDR Compatible".

https://www.cta.tech/News/News-Releases/Press-Releases/2015-...

http://www.whathifi.com/advice/ultra-hd-premium-what-are-spe...

I think NCX is being bit overly negative (in his characteristic style) in his predictions. Sure, there will be cheap crap released, but considering that almost all major manufacturers are pushing this tech heavily on TV screens it can't be that long until it trickles down to monitors too. Of course you can plug your PC right now to one of those fancy new HDR TVs, I'm not sure though if you can get HDR actually working. I guess that would be mostly a software issue?

I didn't say it was. None of that explains what HDR as it relates to monitors means technically. Everything uses the term, but we already have numbers for bit depth of the signal and contrast ratios of the monitor.

So if it isn't just more contrast then what does it actually mean? In images it means the image has values stored above what can be displayed.

I think it's actually a smart choice, as as much as I doubt there will be monitors with that spec, there will for sure be VR headsets that will be able to use it, and likely not that far in the future

What cable transfers 4k 120-144hz? What are the benefits of DisplayPort 1.4 over something like Dual Link DVI or the newest HDMI?

I don't have access to the spec for 1.4, but from what I can understand it's still a single cable that will do 4K 120hz HDR. Obviously it'll have to be a supported 1.4 capable cable, but that's the same as CAT 5 vs CAT 6

Dual link DVI is significantly old-hat compared to the newer DisplayPort and HDMI standards. A single dual link DVI cable can carry either half a 4K frame (1920x2160) at 8 bits per color, 60hz, OR a single 1080p frame at 10 bits per color, 60hz. To get a 4K 60hz display running you need to use two dual link DVI cables, which is insanely bulky. Plus you at best get 8 bit color out of it, and no audio.

The latest HDMI standard can do 4096x2160 60Hz in deep color (12 bits per color).

DisplayPort 1.4 has a higher maximum bandwidth than HDMI 2.0 (31.4 Gbps vs 18Gbps). This allows it to do 120Hz, deep color/HDR or carry multiple 4K streams (multiple monitors or 3D) on one cable. It's by far the most advanced standard out there for consumer video transmission.

Source: I'm an engineer working with video systems, and Wikipedia

Displayport 1.4 is a standard for socket and cable, so it will transfer 4K 120Hz.

Advantages over other standards: https://en.wikipedia.org/wiki/DisplayPort#Advantages_over_DV...

Also, another major advantage - USB Type-C compatibility (http://www.displayport.org/what-is-displayport-over-usb-c/)

Why didn't video cables go optical? Like toslink did w audio?

There are lots of options for optical cabling (e.g. cheap plastic fibers vs. glass fibers) and all have different tradeoffs, e.g. available bandwidth vs. cost. However from what I've seen basically all options are more expensive then equivalent electrical connections (we use both optical and electrical networks in cars).

A major advantage of optical is that there are no EMV problems and that you are electrically decoupled (e.g. no hum loops). This might be one of the reasons why toslink is optical. For displays ground loops are typically no problem compared to amplifiers/speakers.

Thunderbolt was supposed to go optical. You can read about it here, under "Copper vs. optical":

https://en.wikipedia.org/wiki/Thunderbolt_(interface)

USB3 was also supposed to have fiber components. Really hard to find references for this online since at CES 2008 they showed the connectors without any optical stuff, but I found this: http://www.theregister.co.uk/2007/09/19/idf_usb_3_announced/

Anyone know why they didn't end up going optical + copper for USB3?

No advantage. It's still all wires inside the computer and the monitor.

Yes, but inside the computer you have the luxury of static, pre-calculated track layouts that optimise for latency, noise and general integrity. A general purpose, variable length, high bandwidth cable and connectors is a much harder problem, thus the kind of issues we see here sending raw video signals of extremely high fidelity between card and monitor.

Latency and cost, probably.

What latency?

Electric to light to electric would add latency perhaps? Random guess

It wouldn't, not at the scale of inter-device cables.

I wouldn't call it an advantage, but DP1.4 can cheat on the bandwidth department by using lossy compression.

Their press statements it's visually transparent, but the technical overview[1] says this:

> All of the analyses showed that the DSC algorithm outperformed five other proprietary algorithms on these picture quality tests, and was either visually lossless or very nearly so for all tested images at 8 bits/pixel.

[1] http://www.vesa.org/wp-content/uploads/2014/04/VESA_DSC-ETP2...

Ugh, I can see this getting very annoying - having to work out whether something is "true" DisplayPort 1.4.

This screen is supposed to do 4K 120hz, I haven't seen I hands-on review yet though. http://www.144hzmonitors.com/monitors/dell-up3017q-30-inch-4...

How come Thunderbolt 3 still supports only DisplayPort 1.2? Which is the same as what Thunderbolt 2 supported.

It likely has to do with the timing at which the standards were finalized. DP1.3 / DP1.4 probably weren't ready when they needed to finalize TB3. Unfortunate but alas, standards.

Won't something like a Thunderbolt 3 over usb-c be required for a 120Hz HDR 4K vid stream?

DisplayPort 1.4 can support 8K UHD (7680×4320) at 60 Hz with 10-bit color and HDR, or 4K UHD (3840×2160) at 120 Hz with 10-bit color and HDR. 4K at 60 Hz with 10-bit color and HDR can be achieved without the need for DSC. On displays which do not support DSC, the maximum limits are unchanged from DisplayPort 1.3 (4K 120 Hz, 5K 60 Hz, 8K 30 Hz). https://en.wikipedia.org/wiki/DisplayPort#1.4

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