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MacPro not recognizing displays needed 2560x1440,only shows 1920x1200

571 Views 8 Replies Latest reply: Jan 12, 2013 10:17 AM by ginther RSS
ginther Level 1 Level 1 (0 points)
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Jan 9, 2013 6:11 AM



Have a MacPro 1,1 with an ATI 5770 running 10.7.5. Had been running two Dell2407WFPHC displays at 1920x1200. When i swapped out the main display with a Dell2713H the mac only recognizes the 1920x1200 sizes and not the 2560x1440 needed to run the display correctlt.









Mac Pro, Mac OS X (10.7.5)
  • Grant Bennet-Alder Level 8 Level 8 (48,110 points)

    Displays wider than 1920 wide require a Dual-Link connection all the way through.


    Dual-Link means the data lines in all the connectors and cables are doubled, so that it can handle the faster data rates needed to get all those bits on the wider screens.


    Dual-Link uses all the pins in the center grid, so all those pins must be present. Single-Link sometimes (not always) has the center of the grid de-populated to lower cost.


    If you are converting from Mini DisplayPort, you will need a Dual-Link converter. If you ever expect to use all three ports on the display card, you should buy an ACTIVE Dual-Link converter.

    Mac Pro (Early 2009), Mac OS X (10.6.8), & Server, PPC, & AppleTalk Printers
  • Malcolm J. Rayfield Level 5 Level 5 (4,500 points)

    If it's the Dell U2713H, it has DisplayPort and Mini DisplayPort inputs.  If you use one of these, you won't need any adapter.

  • Grant Bennet-Alder Level 8 Level 8 (48,110 points)

    Almost all of these adapters are not reversible -- they convert in only one direction.


    When Apple describes these connectors, they rigorously name the computer-end first (where the signals are generated) then the display-end (where the signals are used). Many other manufacturers are completely sloppy about any similar convention.


    I do not think you should need the expensive Apple Mini DisplayPort --> Dual-Link DVI adapter you cited. I thought you only had one DVI display wider than 1920, and it could plug directly into the Dual-Link DVI port on the graphics card.


    But you are flinging terminology about and re-plugging displays willy-nilly, and I can no longer follow what you-are-plugging-into-what from your various descriptions above.

    Mac Pro (Early 2009), Mac OS X (10.6.8), & Server, PPC, & AppleTalk Printers
  • Grant Bennet-Alder Level 8 Level 8 (48,110 points)

    The "Thunderbolt" cable is a mini-DVI just branded something i assume? That should have worked from what has been said above.

    A ThunderBolt cable is a specialized cable that is ONLY good for connecting a bona fide ThunderBolt port and ThunderBolt devices. You should never have been sold such a cable. It is the wrong cable and will not work for you. The idea that it happens to plug into the ports merely confuses the issue.


    Your graphics card has one Dual-Link DVI port and two Mini DisplayPorts.


    To connect a display that has a mini DisplayPort, use a direct-connect Mini DisplayPort to Mini DisplayPort cable -- all wires, no adapters.


    To connect displays that have only a full-size DisplayPort instead of Mini DisplayPort, use a cable that has a Mini DisplayPort at the computer-end and a DisplayPort at the display-end. This is a straight-through cable that just uses different connectors -- only wires are in it, no adapter.


    To connect a wider-than-1920-wide display that have ONLY DVI, use a Dual-Link DVI cable (all pins in the grid must be present, or it is not Dual-Link).


    Adapters/converters are WAY more expensive than seems reasonable, and are potential points of failure. Avoid them all, if possible.

    Mac Pro (Early 2009), Mac OS X (10.6.8), & Server, PPC, & AppleTalk Printers


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