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Golfmusician

macrumors newbie
Original poster
Mar 27, 2020
8
2
I have a ATI Radeon HD 5770 card in my Mac Pro 5,1 (Mid 2010). It has two Mini Display Port outputs, and a DVI connector. I connected the DVI to my video monitor, and the one of the Mini Display Ports to my Mac. I have another small LCD monitor that I would like hook up through the other Mini Display Port. When I do, my video monitor disappears (DVI). I'm looking for a solution to make this work.
 

Snow Tiger

macrumors 6502a
Dec 18, 2019
854
634
I have a ATI Radeon HD 5770 card in my Mac Pro 5,1 (Mid 2010). It has two Mini Display Port outputs, and a DVI connector. I connected the DVI to my video monitor, and the one of the Mini Display Ports to my Mac. I have another small LCD monitor that I would like hook up through the other Mini Display Port. When I do, my video monitor disappears (DVI). I'm looking for a solution to make this work.

In order to get three concurrent channels of video with an ATI 5770 , one of the mini Display Port channels must have an active video cable attached to it . The other two are permitted to be passively connected .
 

Golfmusician

macrumors newbie
Original poster
Mar 27, 2020
8
2
In order to get three concurrent channels of video with an ATI 5770 , one of the mini Display Port channels must have an active video cable attached to it . The other two are permitted to be passively connected .
Thanks for the quick response. I'm not sure what you mean by an "active" video cable.
 

Snow Tiger

macrumors 6502a
Dec 18, 2019
854
634
Normally , an active cable is one in which there is an electrical charge provided . Ordinary cables have no electrical charges and are thus considered passive .

With Display Port technology however , we have a special situation . Active means the cable also has a signal conversion chip built in that is needed because the source device ( the graphics card ) cannot handle the conversions to all the channels natively concurrently .

With the third display you are attaching to your EFI ATI 5770 , you are required to have an active graphics card cable used ( for one of the mini DP ports - I think its the center port on the bracket ) . Look for a mini Display Port cable advertised with active capabilities . The one you are using now probably is passive .
 

Golfmusician

macrumors newbie
Original poster
Mar 27, 2020
8
2
Normally , an active cable is one in which there is an electrical charge provided . Ordinary cables have no electrical charges and are thus considered passive .

With Display Port technology however , we have a special situation . Active means the cable also has a signal conversion chip built in that is needed because the source device ( the graphics card ) cannot handle the conversions to all the channels natively concurrently .

With the third display you are attaching to your EFI ATI 5770 , you are required to have an active graphics card cable used ( for one of the mini DP ports - I think its the center port on the bracket ) . Look for a mini Display Port cable advertised with active capabilities . The one you are using now probably is passive .
Very cool info. Thank you so much!
 

tommy chen

macrumors 6502a
Oct 1, 2018
907
390
apple says > uce booth miniDP or one miniDP and DVI
better you buy a sapphire pulse RX580 for more
 
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