Display output mysteries

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Luke M

Gawd
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Apr 20, 2016
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The exact display output capabilities of nvidia cards are quite mysterious. Zero documentation beyond "use the plugs that fit".

Example: did you know that the DVI ports are also full fledged HDMI 2.0 ports? 4K, audio, everything.

What about the DP ports? Are they plain DP, or DP++? Etc.
 
Which architecture are you asking about? Pascal I believe can do a max of 4 outputs, HDMI 2.0, Displayport 1.4 or Dual Link DVI ... It does come down to how the mfgs wire them up though?
 
I'm mainly interested in the current stuff (10xx). I did know about the 4 output maximum which seems to be a constant over all nvidia products. But what is the actual native support for each output type? What features require external switches or converters? How does the driver know how things are hooked up?
 
AFAIK, the actual native support for each output are all governed by the port itself, not the GPU (For example, if it has HDMI 2.0, it supports ALL aspects of HDMI 2.0 specifications, same with DP).

The biggest factor when it comes to ports are the numbers on either side of the cable, and it nearly always runs on the lower of the 2. EG a HDMI 2.0 monitor hooked up to a HDMI 1.4 GPU and a HDMI 1.4 monior hooked up ot a HDMI 2.0 GPU would all run at a max of HDMI 1.4. No features within the displayport or HDMI require anything external besides the monitor itself unless you are looking to either convert (HDMI to DP or vice versa) or trying to split the audio from the HDMI, as examples.

EDIT: Also, the DVI port itself cannot support the full specifications of HDMI, as it has a upper resolution limit of 2560x1600, while HDMI 2.0 supports up to 3840x2160@60hz. Chances are it is converted from HDMI 2.0, but it doesn't it can run at HDMI 2.0. In fact, like for like conversions (EG HDMI 2.0 to DP 1.2, both support 3840x2160@60hz maximum) would require an external active converter, but down conversion usually don't.

For the maximum supported resolution, it's faster to look at the specifications of each port and checking them individually, there is no difference between one HDMI 2.0 to another HDMI 2.0 (for example, between GTX 1060 and RX480's HDMI 2.0 ports), as one of the requirements for labeling a GPU having such a port is that they must meet all of that port's specifications, no less. You will not see a GPU labeled HDMI 2.0 unable to support 4k@60hz for example, unless the display itself is not HDMI 2.0. This also applies to the display end. If a HDMI 2.0 display is hooked up to a HDMI 2.0 GPU, you can expect that all features within HDMI 2.0 specifications to be available.
 
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chenw said:
EDIT: Also, the DVI port itself cannot support the full specifications of HDMI, as it has a upper resolution limit of 2560x1600, while HDMI 2.0 supports up to 3840x2160@60hz. Chances are it is converted from HDMI 2.0, but it doesn't it can run at HDMI 2.0. In fact, like for like conversions (EG HDMI 2.0 to DP 1.2, both support 3840x2160@60hz maximum) would require an external active converter, but down conversion usually don't.
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See, this is the kind of thing I'm talking about. I even mentioned in the first post that this was not the case! People don't know what nvidia cards can and can't do. They're just making assumptions.
 
Have you actually tried running a 4k/60hz monitor through the DVI-D port at 4k/60hz?

EDIT: The reason I am asking is because I am running entirely on the specifications of HDMI and DVI-D themselves, rather than "speculating", and DVI-D specification simply do NOT have enough bandwidth to BE HDMI 2.0.

It can be POWERED by HDMI 2.0, but it does not necessarily mean it can RUN at HDMI 2.0 specifications. All points to the fact that it most likely will not.

For the record about Display port: no, there is no "hidden" displayport features. It either has everything within the DP specifications and run all features listed on it, or it doesn't. The only thing that could be different would be the type of port, some cards (particularly the 6 display supporting firepros) and laptops uses miniDP instead of full size DP, but functionally they are DP. The things that sets DPs apart from each other, like HDMI, are the numbers. The exact number matter.

EG DP 1.2a is different spec from DP1.2, in the same way that HDMI 2.0 is different from HDMI 2.0b
 
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chenw said:
Have you actually tried running a 4k/60hz monitor through the DVI-D port at 4k/60hz?

EDIT: The reason I am asking is because I am running entirely on the specifications of HDMI and DVI-D themselves, rather than "speculating", and DVI-D specification simply do NOT have enough bandwidth to BE HDMI 2.0.
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Yes, of course I tried it.

chenw said:
For the record about Display port: no, there is no "hidden" displayport features. It either has everything within the DP specifications and run all features listed on it, or it doesn't. The only thing that could be different would be the type of port, some cards (particularly the 6 display supporting firepros) and laptops uses miniDP instead of full size DP, but functionally they are DP. The things that sets DPs apart from each other, like HDMI, are the numbers. The exact number matter.
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The numbers? Is "++" a number? :)
 
Luke M said:
Correct.
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Double checking, so you basically used a DVI-D to HDMI converter on the DVI-D port to connect to your TV via HDMI, or does the TV have DVI-D port?

Luke M said:
I don't understand.
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EDIT: Actually, nevermind about the DP++, I made an error on my part and COMPLETELY misunderstood your question.

My short answer is I have no idea if GPUs have DP++ built in, as I never use converters of any sort when it comes to HDMI or DP displays.
 
Luke M said:
The TV has only HDMI inputs.
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OK, that might explain it. If you connected via DVI-D and then HDMI converted it back into HDMI, no processing is done on the DVI-D standard, so you are still using HDMI, with DVI-D port as a middle man connection, you are not connecting via DVI-D at all it seems.
 
Luke M said:
The exact display output capabilities of nvidia cards are quite mysterious. Zero documentation beyond "use the plugs that fit".

Example: did you know that the DVI ports are also full fledged HDMI 2.0 ports? 4K, audio, everything.

What about the DP ports? Are they plain DP, or DP++? Etc.
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DVI does not support the optional Ethernet that HDMI does, and audio transmittal has to be supported on both devices that are connected with DVI while it's implicit with HDMI. Dual link DVI at most can do 3840x2160 at 30-40 Hz with 8-bit color, while HDMI 2.0 supports up to 60 Hz at the same resolution and color depth. 4K also usually has to be forced through a custom resolution when using DVI, as far as I know.

Aside from that, HDMI partners are not allowed to advertise what version their devices have. There is only regular HDMI and "High speed" HDMI. It causes some confusion on the consumer end, but it's supposed to prevent manufacturers from price gouging. I don't know what the advertising practices are for DP. Despite that, NVIDIA freely shows that the outputs on their 10 Series video cards are equipped with DP 1.4 and HDMI 2.0b.

Regardless, why would you not "use the plugs that fit?" If your television only has HDMI inputs and your video card has an HDMI output, why would insert a middleman in that link? Just use a high speed HDMI cable. If all else fails, just RTFM. All displays will include instructions on which interfaces and cables to use for any given resolution target.
chenw said:
Double checking, so you basically used a DVI-D to HDMI converter on the DVI-D port to connect to your TV via HDMI, or does the TV have DVI-D port?


EDIT: Actually, nevermind about the DP++, I made an error on my part and COMPLETELY misunderstood your question.

My short answer is I have no idea if GPUs have DP++ built in, as I never use converters of any sort when it comes to HDMI or DP displays.
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The 1080 Ti at least supports DP++, otherwise they wouldn't be able to include a passive DVI-D converter. It's important to note, though, that DP++ still only supports single link DVI bandwidth passively (meaning no practical 4K support).
 
Armenius said:
The 1080 Ti at least supports DP++, otherwise they wouldn't be able to include a passive DVI-D converter. It's important to note, though, that DP++ still only supports single link DVI bandwidth passively (meaning no practical 4K support).
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FYI, passive is a misnomer. DP++ to DVI/HDMI adapters include an active voltage level converter. Also, it's entirely possible for DP++ to support 4K (HDMI 2.0 is single-link if you don't know), but it's unclear if anyone has bothered to make a "passive" adapter that supports it.
 
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