Need help connecting third display to 7970 card

freehurricane

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Jan 9, 2013
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I have a VisionTek Radeon HD 7970.

I am trying to connect 3 displays to my video card. I have the following outputs on my card

2x Mini displayport

1x HDMI

1x Dual DVI

I have currently have one monitor connected via dual dvi and another connected via HDMI

The third display I am trying to connect is a tv that only accepts HDMI connections. To connect the third device, I purchased this active Mini dp to hdmi adapter.

http://smile.amazon.com/gp/product/B00AYAF3MQ/ref=oh_details_o00_s00_i00?ie=UTF8&psc=1

However, It is not working. When the tv is connected through the adapter, I do not see anything on the tv, nor do I see the display detected in catalyst. I have tried hooking up the tv directly to the hdmi port and it works. I have also tried hooking up the other monitor, which is currently connected via HDMI, to the adapter and it DIDN'T work.

Is the adapter the problem? I researched hooking up 3 displays to one card, and it seemed like as long as the mini dp to HDMI adapter was ACTIVE, it would work. Other reviewers on Amazon also mentioned that the adapter worked for them

Is there a setting that needs to be enabled in software somewhere for the card to use the mini dp connection?

Maybe I should just use an active Mini dp to dvi adapter, and then use a dvi to hdmi cable?

Thank you
 
Solution
I'm guessing the adapter is just faulty, as an active adapter is all you need, i have a 7850 running 4 monitors with a DVI, HDMI, and two of those active Mini DP adapters with no problems.

freehurricane

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I am opening catalyst control, going to desktop management->creating and arranging desktops

and then clicking "detect displays"
 

freehurricane

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It is an Insignia LCD tv with 1080p resolution.

I tried the adapter with the second monitor, it did not work.

The tv did work when hooked directly up to the hdmi port
 

Jaxem

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Try it as well from the windows one right clicking the desktop and the screen resolution menu. Also make sure your TV is set to the right input as the computer won't detect anything if the TV is set to different input, even if it's on.
 
Right, if you have a three monitor setup you must use and active link display adapter from the display port of the card.

It states this on the visiontek website.

To enable more than two displays, additional panels with native DisplayPort™ connectors, and/or DisplayPort™ compliant active adapters to convert your monitor’s native input to your cards DisplayPort™ or Mini-DisplayPort™ connector(s), are required.

http://www.visiontek.com/7000-series/hd-7970.html

The message you will or should currently get with the setup you have is an error in CCC when setting up one of the monitors.

Something about Identification and an error in creating the config/ or profile for it. Saving it. when trying to set up three monitors in the way you are.

When trying to connect monitors without using an active display port adapter.


 

freehurricane

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I made sure the tv was on the correct input and just tried, the tv is not showing up in windows screen resolution menu either.
 

freehurricane

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I tested the hdmi cables, they both work. The problem does seem to be the something to do with the adapter.

Either I haven't set it up right or it is defective. I may end up return ing it
 

freehurricane

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The adapter I have purchased IS active, though. It states that on the amazon page, and other reviewers on the amazon website have mentioned that they used the same adapter I purchased to get three screens working
 

freehurricane

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Ok, thank you. I will look into returning the adapter
 
If you have an active display port adapter, you must make sure, if plugged into the display port that the Usb power feed is plugged into the side.
Or it will not work.

If you do not have the usb port for power it is not an active adapter for the display port to a monitor ect. So will not support 3 monitors.

Because believe it or not a display port does not produce enough signal voltage for a bridged interface.
It will only do display port to display port of a monitor equipped with the port. Cross video connection Hdmi Dvi or VGA requires the 5+ v volts connected to the active display port breakout box. in such a case.

 

Jaxem

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Many active adapters are powered from the port, none of mine use external power and they're definitely active.
 
There is a confusion in this, and belive me it can depend on the brand of card used.
With some you can get away with an adapter with no extra usb power plugged into it.

But have problems when trying to connect it to a device.
While with others it requires a 5+ usb volt supply to create and active link between the card. Via a DAC to get the right clocks to display the image on the two bridged video interfaces.

The way it works is like this.
When you connect a monitor it relays it`s settings to the card. It`s resolution display set, and the clock frequency of each set resolution it can display in Hz.

The card then takes note of these and sets up the list to sync for display out put to the device or monitor.

If the adapter cannot relay the information from the monitor or display port to the graphics card.

Ie: unable to save monitor or profile in ccc for the monitor it is why. The Dac of the card cannot obtain or set the clock or Hz range or resolution.

To display the image. it needs to know the capability of the connected display device through the.
EDID chip of the monitor, or display device first.