The wonderful world of Displayport connectors: Are special converters needed?

Petros_k

Member
Jan 20, 2014
149
0
71
General question about what to do when one device has a displayport type connector (and of course there's all kinds of contradictions on the Internet. So...)

I know displayport carries a digital signal, just like DVI and HDMI. But in general I'm finding when your device INPUT is displayport and your OUTPUT is HDMI or DVI, you're out of luck for a simple solution. Good thing that's not my problem.

What I want to do is connect a displayport OUTPUT from a video card like you see here: http://www.nvidia.com/object/product_quadro_fx_580_us.html to an HDMI monitor INPUT, and I can't find an honest straight forward answer trying to just Google it. I know that there are cables available that have male displayport on one end and male HDMI on the other, but does this work all the time or do you need a special "adapter" that does some kind of "conversion"? The terms "adapter" and "converter" are not always interchangeable, so I can't understand the wide array of info out there.
 
Last edited:

Insert_Nickname

Diamond Member
May 6, 2012
3,797
475
126
I know that there are cables available that have male displayport on one end and male HDMI on the other, but does this work all the time or do you need a special "adapter" that does some kind of "conversion"?
I'll try to keep it simple... ;)

In general, yes. A DisplayPort cable with a DisplayPort male and HDMI male should be plug'n'play. This applies to both HDMI and DVI, because the DisplayPort is able to transmit a DVI/HDMI signal with a simple passive adaptor that's built into the cable. (or rather the connector)

This assumes you're using a DP++ certified port. (almost all are)

There is one caveat though. If you need dual-link DVI, it requires that you use what is called an active converter. This is usually takes the form of an external dongle that requires its own power supply.
 

JackMDS

Elite Member
Super Moderator
Oct 25, 1999
29,031
241
106
Plugs/adapters are just dumb mechanical arrangement of pins. Many of them look impresive because they are coated with gold but they are really Dumb.

It is important to understand what behind the plug/jack its level of technical/electronic compatibly.

Example:

This is a USB cable to transfer files from one computer to the another.

The thing with the Blue Dot in the Middle is an electrical devices to mitigate the capacity of file transfer.

Just plugging a Regular USB wire with two type A plugs would do nothing, or may be would fry the motherboards because of the 5V ruing through it..


:cool:
 

Petros_k

Member
Jan 20, 2014
149
0
71
For those just as lost as me on this: Single link DVI is able to transfer 1920 x 1080 resolution but dual link can go to 2048 x 1536. For the DVI output on the video card (it has 1 dual-link DVI-I and 2 DisplayPorts, see below) I only need to send it to an LCD monitor that has a native resolution of 1366 x 768, and its compatible with both a 720p and 1080p digital connection. But this is for the DVI connector on the graphics card, not the DisplayPort.

For the DisplayPort output, it needs to go to a 19" LCD monitor that has an HDMI input, and the resolution here is also smaller than 1920 x 1080.

I have seen this term "passive adapter," which simply means there is no electronic conversion. The wires in the cable simply correspond to the pins of the two different connectors in the correct way so that the cable works. That's why saying something like there's "a simple passive adapter that's built into the cable" is misleading. I found some info while waiting for an answer here. This is good:

"No offense to anyone here, or on any of the other forums that deal with this fuzzy topic, but this topic is so horribly covered, to date. I am trying to save time and frustration here...

As far as I can tell, all of the $10-$20 DisplayPort->HDMI adapters out in the market, WILL NOT WORK IN THE REVERSE DIRECTION (meaning HDMI->DisplayPort). These cheap passive adapters (I own a few) only handle DisplayPort output from a video card (or laptop) to an HDMI monitor input." http://www.tomshardware.com/forum/64251-3-hdmi-display-port

I assumed a male-Displayport to male-HDMI cable would work, but like I said I fond all kinds of confusing info (even here, because now it looks like if the video card isn't DP++ it won't work ). And it's important to keep in mind this cable will only work if your output is Displayport and your input is HDMI.
 
Last edited:

Petros_k

Member
Jan 20, 2014
149
0
71
NVIDIA Quadro FX 580 512MB Graphics Card

Connectors:
* 2 DisplayPort, 1 Dual-Link DVI-I.

Maximum Resolution:
* Two DisplayPort outputs drive two digital displays up to 2560 x 1600
* One dual-link DVI-I output drives one digital display at resolutions up to 2560 x 1600 @ 60Hz or one analog display at resolutions up to 2048 x 1536 @ 85Hz

NOTE: This card supports up to two displays.




Does that sound like it's DP++ certified? The video card is in a HP computer that's from 2008.
--and just to clarify, if it's not DP++ certified, it 's not that the DisplayPort to HDMI cable won't work; it will only work like a single-link DVI connection, which restricts the resolution to 1920 x 1080, right?

Something tells me I got it wrong...:confused:

The wiki link says:

"The DisplayPort signal is not compatible with DVI or HDMI. However, Dual-Mode DisplayPorts [DP++] are designed to transmit a single-link DVI or HDMI 1.2/1.4 protocol across the interface through the use of an external passive adapter that selects the desired signal and converts the electrical signaling from LVDS to TMDS. Analog VGA and dual-link DVI require powered active adapters to convert the protocol and signal levels, and do not rely on Dual-Mode. VGA adapters are powered by the DisplayPort connector, while dual-link DVI adapters may rely on an external power source."

So then unless the DisplayPorts are DP++ I can't use the male-DisplayPort to male-HDMI cable suggested above. And if it's NOT DP++ then I can't use it unless the monitor has a DisplayPort? That would make little sense within the context of the specs from the HP manual for the Quadro FX 580 graphics card.
 
Last edited:

Petros_k

Member
Jan 20, 2014
149
0
71
I see that HP made these at one time for their workstations:

http://h18000.www1.hp.com/products/quickspecs/13111_div/13111_div.PDF

They show a cable that converts DisplayPort to HDMI. Not sure if it's passive or active. On the second page the XW4600 (the system that has the above mentioned FX 580 graphics card) is listed under compatibility, but I can't tell are they putting this in a list of computers that you need to CHECK compatibility. Ridiculous.
 
Last edited:

Petros_k

Member
Jan 20, 2014
149
0
71
From HP in 2010:
http://h20331.www2.hp.com/hpsub/downloads/HP-DisplayPort-setup.pdf

"What’s the best way to setup a dual-monitor configuration when I have a mix of DVI and DisplayPort outputs?
On graphics cards with both DVI and DisplayPort outputs, if the DVI connection is active it will always be the default display. It is usually more straightforward to configure the display attached to the DVI output first, and then configure DisplayPort displays after this has
been completed. Most currently shipping graphics cards have three outputs, any two of which may be used to create a multiple display setup. For information on what cables and adapters are needed for a variety of DisplayPort configurations, including a mix of
DisplayPort, DVI, and VGA monitors, see the DisplayPort Configuration Mini White Paper."

DisplayPort Configuration Mini White Paper (2009):
http://h20331.www2.hp.com/hpsub/downloads/DisplayPort_Configs_MWP.pdf

Here, the Quadro FX 580 is listed as one of their Nvidia 3D graphics cards. In the fine print it says: "Each graphics card can support a maximum of 2 displays, except for the NVIDIA Quadro NVS 450 which supports 4." HDMI monitor connections are not listed anywhere.


However, if you see this 2009 HP white paper:
http://h20331.www2.hp.com/hpsub/downloads/DisplayPort_Setup_MWP.pdf

They list the adapters sold by HP for DisplayPort that come with their graphics cards. For DisplayPort to DVI it says "uses dual-mode capability of DisplayPort output." This means the Displayport must be DP++ certified, and it likely is a passive connection adapter. In contrast, to do DisplayPort to either DVI Dual-Link (not to be confused with dual-mode) or Displayport to VGA the adapter is listed as an "active device." The question remains though if DisplayPort to DVI (passive adapter) is interchangeable with DisplayPort to HDMI. The only clue I have is this: "Displays with HDMI inputs can be used with a non-HP DisplayPort to HDMI adapter." Again, no mention of is the adapter for HDMI passive or active. You'd assume it can be passive because the DisplayPort to DVI (non dual-link) is likely a passive adapter.

I know it sounds like I'm answering my own question, but I'm just not 100% sure!
 

Insert_Nickname

Diamond Member
May 6, 2012
3,797
475
126
For those just as lost as me on this: Single link DVI is able to transfer 1920 x 1080 resolution but dual link can go to 2048 x 1536.
Dual-link DVI doesn't have a maximum resolution per se, but the practical maximum is 2560x1600 (or 1600p)...

They show a cable that converts DisplayPort to HDMI. Not sure if it's passive or active.
DisplayPort can output a HDMI signal natively, just using a passive adaptor or cable with DisplayPort in on end and HDMI in the other.

Of course you can also get something that does exactly the reverse. Such a converter needs to be active. Problem is that its bloody expensive.

http://www.lindy-international.com/HDMI-DVI-to-Mini-DisplayPort-Convertor.htm?websale8=ld0101.ld020102&pi=41047

Notice the price is 125€ (~$169)...
 
Last edited:

Petros_k

Member
Jan 20, 2014
149
0
71
DisplayPort can output a HDMI signal natively, just using a passive adaptor or cable with DisplayPort in on end and HDMI in the other.

Only a "Dual-Mode DisplayPort" (DP++) output will do this for an HDMI or DVI input, and you will only get single-link resolution (1920 x 1080 maximum).

My basic problem is that I do not know if the DisplayPorts on the Quadro FX 580 are DP++
 

Petros_k

Member
Jan 20, 2014
149
0
71
Spoke to HP tech. Guy was really unsure about the details of their graphics card. He said it was "two generations old already." He said when he looked at the specs for the Quadro FX 580 the info on the DisplayPort output says nothing about being DP++ (he claimed to know what this means). He said he'd have to assume it is NOT DP++ but the original type, which is just called "DisplayPort."

He said that you can use an ACTIVE adapter in all cases (for DP++ as well as the original DP), and that if it's only the first version of DP and you try to use only a passive cable it will not work. His only recommendation (given how "old" the PC is) is to buy both cables and see which one works.

So now I'm set to waste money on at least one cable.
 
Last edited:

kevinsbane

Senior member
Jun 16, 2010
694
0
71
Only a "Dual-Mode DisplayPort" (DP++) output will do this for an HDMI or DVI input, and you will only get single-link resolution (1920 x 1080 maximum).

My basic problem is that I do not know if the DisplayPorts on the Quadro FX 580 are DP++
Is there a symbol that looks like this over the DP port?

 

Petros_k

Member
Jan 20, 2014
149
0
71
I realize that if the symbol is present it means DP++ compatible, and I would have no issue. I do not have the graphics card (the system is being shipped to me). The only photo I have of the back of the computer shows the graphics card in such a way that I cannot tell if it's got a DP++ over the ports. Scroll down and you can see it here:
http://www.ebay.com/itm/HP-xw4600-Workstation-Intel-Core-2-Duo-E8400-3-00GHz-2GB-250GB-Windows-7-A1083-/380825967284?pt=Desktop_PCs&hash=item58aaff1ab4

or copy and paste this into your browser:
http://i.ebayimg.com/00/s/MTIwMFgxNjAw/z/SKgAAOxyOlhSzre9/$_57.JPG

I spoke with someone from HP who said there's no mention of DP++ in the specs for the graphics card.

Remember too, this system was sold in 2008, and I do not know if DP++ graphics cards were even available at the time.
 
Last edited:

Petros_k

Member
Jan 20, 2014
149
0
71
At this link are the DisplayPort adapters sold by HP:

http://h18000.www1.hp.com/products/quickspecs/13111_ca/13111_ca.PDF

You can see the first type they offer is a DiplayPort to HDMI type, but they do not indicate if this is an active or passive adapter (nor do they do this for the DisplayPort to DVI adapter). It says the DisplayPort to HDMI adapter is compatible with an HP XW4600 Desktop, but that doesn't tell me much. I'm not even wasting my time trying to ask HP tech support. I'll get someone who just says "Uhhhh, Uuhhhh. Hmmmmmm."
 
Last edited:

mfenn

Elite Member
Super Moderator
Jan 17, 2010
22,403
5
71
www.mfenn.com
I dunno if you'll be able to definitively answer this question until you have the system in hand. Unless it's really critical that you get the system up and running as quickly as possible, I don't see the harm in trying the $8 passive cable.

My 2c is that it will probably work. The FX 580 is the Quadro version of the 9400 GT, which is what Apple used when they went to DP, but needed to preserve DVI, HDMI, and VGA compatibility.
 

Petros_k

Member
Jan 20, 2014
149
0
71
I dunno if you'll be able to definitively answer this question until you have the system in hand. Unless it's really critical that you get the system up and running as quickly as possible, I don't see the harm in trying the $8 passive cable.

My 2c is that it will probably work. The FX 580 is the Quadro version of the 9400 GT, which is what Apple used when they went to DP, but needed to preserve DVI, HDMI, and VGA compatibility.
If "The FX 580 is the Quadro version of the 9400 GT, which is what Apple used when they went to DP" then it's likely the first version of DisplayPort, which is not supposed to be compatible with HDMI or DVI (according to the wiki link http://en.wikipedia.org/wiki/DisplayPort ) See post #6 above.

What I'm also doubting is that the FX 580 (from 2008 or so) lacks the popular Eyefinity type architecture in which many people now know that with a Radeon you can easily do 2 monitors with DisplayPort and then you only need an active adapter if you want a THIRD monitor. I only need 2. I just cannot locate the specs on a Quadro FX 580 to see for sure it is DP++ certified. Given the HP tech also did not know, he gave me the rule of thumb: Active converter cables will work for both first version DP as well as DP++ (even though you don't need it for the latter). Of course, when active cables are $30 or so, I could forget about messing with cables and just replace the used graphics card with a new one of the same or better quality that doesn't mess around with DisplayPort and I'd be paying the same. Look: XFX HD-545X-ZQH2 Radeon HD 5450 1GB 64-bit DDR3 PCI Express 2.1 x16 HDCP Ready Low Profile Ready Video Card - Newegg.com
 
Last edited:

Insert_Nickname

Diamond Member
May 6, 2012
3,797
475
126
If "The FX 580 is the Quadro version of the 9400 GT, which is what Apple used when they went to DP" then it's likely the first version of DisplayPort, which is not supposed to be compatible with HDMI or DVI (according to the wiki link http://en.wikipedia.org/wiki/DisplayPort ) See post #6 above.
Whoa, all versions of DP can be dual mode (DP++) compatible. Weather or not DP is compatible with DVI/HDMI has nothing to do with what version a DisplayPort is.

Newer versions add support for things like higher resolution, multi channel audio, greater colourspaces and such.
 

Petros_k

Member
Jan 20, 2014
149
0
71
Whoa, all versions of DP can be dual mode (DP++) compatible. Weather or not DP is compatible with DVI/HDMI has nothing to do with what version a DisplayPort is.

Hang on there then, because this is the first time (from three forums, many posts, and a phone call to HP) anybody has said this, and Wiki (not that Wiki is some ultimate authority) does not explicitly state this.

"All versions of DP" would mean any DisplayPort interface. But take a look at this:

"VGA requires a separate converter device. DVI and HDMI supported only when DisplayPort source device has DP++ capability, and require a separate adaptor. LVDS is an interface internal to laptops and TV’s, so conversion must be designed in to those devices. Full DisplayPort resolution not supported on non-DisplayPort devices." http://www.displayport.org/get-connected/

In the diagrams at the above link, they are indeed distinguishing between "dual-mode" DisplayPort (or DP++) and something they show as simply "DP." They say specifically, "DVI and HDMI supported only when DisplayPort source device has DP++ capability, and require a separate adaptor."

And here as well:

"DisplayPort-to-HDMI adaptors and DisplayPort-to-DVI adaptors are very simple and only operate one way. For instance, when a DP-to-HDMI adaptor is connected to a PC that supports DP++ (Dual-Mode) capability, the PC senses the presence of the adaptor and sends HDMI signals over the DisplayPort connector rather than DisplayPort signals. No signal conversion is performed by the HDMI adaptor. HDMI signals are merely passed through. The unique DisplayPort adaptor capability enables the PC to connect to a variety of displays via the DisplayPort connector including HDMI, DVI, and VGA. VGA adaptors are more complex and perform active signal conversion from DisplayPort to VGA. These adaptors also operate only one way." http://www.displayport.org/faq/

--am I missing that the DP++ capability is a matter of the driver for the graphics card?

And here as well:

"A Dual-Mode DisplayPort source is a device, such as personal computer, that can logically output either DisplayPort or TMDS (Transitional-Minimized Differential Signaling) from the DisplayPort output connector, enabling the support of DisplayPort, DVI, and HDMI monitors. An additional device, specifically a Dual-Mode DisplayPort cable adaptor, is required to convert the mechanical connector, as well as the electrical aspects of the signal, to output that is compatible with a DVI or HDMI cable and display. A Dual-Mode DisplayPort source automatically detects the presence of a plugged-in Dual-Mode DisplayPort cable adaptor and provides the DVI or HDMI signal, as required, to support the connected DVI or HDMI monitor." http://www.vesa.org/news/vesa-introduces-updated-dual-mode-standard-for-higher-resolution-interoperability-with-hdmi-displays/

I know that I read somewhere that the DP++ designation needs to be implemented by the device manufacturer. Again, the HP tech gave me the impression that without the active adapter a "regular" DP (not DP++) will simply not work at all unless you use an active adapter. I made it clear the output was DisplayPort and the input was HDMI. He said he didn't think a passive cable will work.

Please correct me if you think I still got it wrong...
 
Last edited:

Insert_Nickname

Diamond Member
May 6, 2012
3,797
475
126
"VGA requires a separate converter device. DVI and HDMI supported only when DisplayPort source device has DP++ capability, and require a separate adaptor. LVDS is an interface internal to laptops and TV’s, so conversion must be designed in to those devices. Full DisplayPort resolution not supported on non-DisplayPort devices." http://www.displayport.org/get-connected/
I don't see the contradiction in that. A DisplayPort can be either DP or DP++ compatible, but everything back to version 1.0 can be DP++ compatible.

Its how the manufacturer chooses to implement the given DisplayPort on a graphics card that's important. If a port is DP++ compliant, it should be clearly marked with a DP++ logo near the port. If there is no logo, then chances are its not DP++ compliant, but I haven't seen anything without in a long time. Especially on professional-level gear.

VGA is diffent BTW. Because its analogue it'll always require a DAC to convert from digital to analog. Its just that that DAC has always been built into the graphics card. Its no different then when you use a DVI-VGA adaptor. The DVI port is then configured to analog mode, and the internal DAC takes over. There is (or was, more like) such a thing as analogue DVI (DVI-A).
 

Petros_k

Member
Jan 20, 2014
149
0
71
Another example of a distinction being made:

"Your computer may include a simple DP icon if it is regular, or a DP++ icon that indicates your computer supports multi-mode DisplayPort for use with different data types."
http://www.ehow.com/info_12216697_multimode-display-port-vs-display-port.html

I don't think it can get any clearer than this:

"Because traditional DP is not compatible with other signal types, you must use input and output devices that both offer DP ports if you have no adapter. However, you may be able to use a DisplayPort output with an input device if you purchase an active adapter. The adapter itself transmits the signal to DP to HDMI or DVI, for example. If you purchase a passive adapter, you will not be able to pair a DisplayPort output with a passive cable. However, multi-mode [same as dual-mode, or DP++] output devices are able to work with a passive adapter, which you can usually purchase for a lower price."

This information is not correct?
 
Last edited:

Petros_k

Member
Jan 20, 2014
149
0
71
One more (scroll all the way down):

"native DisplayPort uses a different protocol, different signalling and a different electrical interface to what DVI/HDMI does. However, dual-mode DisplayPort (DP++) interfaces allow the interface to use the same protocol and signalling as DVI/HDMI, and a semi-passive (voltage-translating) adaptor is needed to interface the different electrical interface of a HDMI/Single-Channel DVI display.

If the DisplayPort is not dual-mode capable, then you will need an active adaptor to act as a DisplayPort sink and output through HDMI."

http://forums.overclockers.com.au/showthread.php?t=1051439

In all of these links someone is differentiating between a "regular" (not dual-mode) DisplayPort and a "dual-mode" (DP++) DisplayPort. And here, he's saying the "regular" Displayport output requires an active adapter even for HDMI input.
 
Last edited:

mfenn

Elite Member
Super Moderator
Jan 17, 2010
22,403
5
71
www.mfenn.com
If "The FX 580 is the Quadro version of the 9400 GT, which is what Apple used when they went to DP" then it's likely the first version of DisplayPort, which is not supposed to be compatible with HDMI or DVI (according to the wiki link http://en.wikipedia.org/wiki/DisplayPort ) See post #6 above.
I think you missed the key part of my post:

My 2c is that it will probably work. The FX 580 is the Quadro version of the 9400 GT, which is what Apple used when they went to DP, but needed to preserve DVI, HDMI, and VGA compatibility.
In other words, if you have an Apple machine with a 9400 GT, then you could use DVI, HDMI, and VGA with simple passive adapters.
 

mfenn

Elite Member
Super Moderator
Jan 17, 2010
22,403
5
71
www.mfenn.com
Another example of a distinction being made:

"Your computer may include a simple DP icon if it is regular, or a DP++ icon that indicates your computer supports multi-mode DisplayPort for use with different data types."
http://www.ehow.com/info_12216697_multimode-display-port-vs-display-port.html

I don't think it can get any clearer than this:

"Because traditional DP is not compatible with other signal types, you must use input and output devices that both offer DP ports if you have no adapter. However, you may be able to use a DisplayPort output with an input device if you purchase an active adapter. The adapter itself transmits the signal to DP to HDMI or DVI, for example. If you purchase a passive adapter, you will not be able to pair a DisplayPort output with a passive cable. However, multi-mode [same as dual-mode, or DP++] output devices are able to work with a passive adapter, which you can usually purchase for a lower price."

This information is not correct?
I don't think that anybody is disputing that it is possible to implement DP with or without the TMDS transmitters needed to support DP++ and with or without the DAC needed to support VGA.

I think you're trying to extract a fine distinction where there really isn't one in common usage. Just because the copy says "DP" instead of "DP++" or "multi-mode DP", or "dual-mode DP", does not mean that the device isn't DP++ capable. If does have one of the more specific terms, then you know it is DP++ capable, but the converse isn't true.

Perhaps it would be better if everybody used one of the more specific terms, but they don't, so you can't use the lack of the specifier to determine that the feature isn't there.
 

Insert_Nickname

Diamond Member
May 6, 2012
3,797
475
126
"Because traditional DP is not compatible with other signal types, you must use input and output devices that both offer DP ports if you have no adapter. However, you may be able to use a DisplayPort output with an input device if you purchase an active adapter. The adapter itself transmits the signal to DP to HDMI or DVI, for example. If you purchase a passive adapter, you will not be able to pair a DisplayPort output with a passive cable. However, multi-mode [same as dual-mode, or DP++] output devices are able to work with a passive adapter, which you can usually purchase for a lower price."

This information is not correct?
Its correct.

I think you're mixing a few things up though. There is the DisplayPort version (1.0, 1.1a, 1.2 and future 1.3), that determines what level of features/resolution a given port supports.

Then there is the DisplayPort Dual-mode Standard (DP++ or multi-mode DisplayPort). This can be either version 1.0 or 1.1. However support for this standard is optional for the manufacturer of the device using a DisplayPort.

A DisplayPort has to be compliant to the first, but not necessarily to the second.

In all of these links someone is differentiating between a "regular" (not dual-mode) DisplayPort and a "dual-mode" (DP++) DisplayPort. And here, he's saying the "regular" Displayport output requires an active adapter even for HDMI input.
This is 100% true, but that is also exactly the point I have been trying to make. Perhaps there has been a misunderstanding... ;)
 

ASK THE COMMUNITY