Mini Port to DVI-I Dual Link...Is it possible?

Discussion in 'Mac Accessories' started by kcotton222, May 8, 2009.

  1. kcotton222 macrumors newbie

    May 8, 2009
    Can anyone suggest the best adapter to go from (Mini Port Display to apple VGA or DVI-D adapter) to (adapter) to (DIV-I Dual link Male to RGB cable).
    See cable

    Follow this link for a DVI Guide

    Possible solutions?
    1. (Apple Mini Display Port to VGA female adapter) to (male VGA to DVI-I Dual Link female adapter) to (male DVI-Dual Link to RGB cable).
    See adapter

    2. (Apple Mini Display Port to DVI-D female adapter) to (male DVI-D Dual Link to DVI-I Dual link female adapter) to (male DVI-I Dual Link to RGB cable).
    See adapter
  2. xraydoc macrumors demi-god


    Oct 9, 2005
    I do not believe your concoction will work.

    First, a DVI-I connector carries both digital and analog signals. The DVI-I to component/RGB cable you've shown there breaks out the analog signals, not the digital signals.

    The Apple mini-DP to DVI adapter will output digital signals only, not analog (i.e., its DVI-D, not DVI-I).

    You could use the mini-DP to VGA adapter, then use a VGA-to-component/RGB transcoder.

    What is it that you need an RGB signal from your Mac for? Does your display device not accept a VGA signal? What about DVI or HDMI input on your display? Going from DVI to HDMI is as simple as a small connector adapter (HDMI is DVI-D + optional HDCP encryption + optional multichannel audio).
  3. alphaod macrumors Core


    Feb 9, 2008
    There is only 1 Dual-link DVI adapter for miniDP and it's the one Apple makes; It's also DVI-D and you cannot attach any other adapters to it. It sucks I know.
  4. kcotton222 thread starter macrumors newbie

    May 8, 2009
    This is to watch movies from the Macbook Pro to a projector. The projector takes RGB and VGA. However, I'd only like to have one cable going to the projector (RGB). Why? 1) My current VGA cable is not long enough (10feet). 2) I already purchased the DVI to RGB cable $25. I'd like to use the damn thing now. 3) I already purchased the RGB video switcher $50. I would like to use it too. 4) I already purchased the Apple "Mini DP to DVI" which is a loss at this point unless apple lets me return it. I think they will let me exchange it for the VGA adapter.

    Would solution #2 work with the (male VGA to DVI-I Dual Link female adapter)? What exactly is the "VGA-to-component/RGB transcoder" you suggest? Is this different from the (male VGA to DVI-I Dual Link female adapter)?

    I know I totally have complicated this situation by jumping the gun and buying these items before I knew what I was doing or understand DVI and the Mini Port (I just bought this MAC, my first one). I also realize I should have just stuck with the VGA adapter and cable. Can I salvage the $100 I have invested in the RGB cable and switcher and find a solution without spending too much money?

    Thank you!
  5. xraydoc macrumors demi-god


    Oct 9, 2005
    I really think you should try to return what you've bought so far. You'll never get an analog signal (what you're after) from a mini-Display Port to DVI connector - these send digital signals only. No analog.

    That DVI-to-RGB cable you bought is strictly for DVI-I/DVI-A signals. It'll do no good with a digital DVI (DVI-D) signal, which is what your display port-equipped Mac will output thru a mDP-to-DVI or mDP-to-DualLink DVI adapter.

    You need a mini-DP to VGA, then run a VGA cable to the projector.

    Unfortunately, it appears as if you jumped the gun and bought equipment based on what the connector looked like but without realizing that many incompatible formats can be carried by the same or similar connectors.

    As for the "transcoder", what I was referring to are usually small powered boxes that will convert a VGA signal (15-conductor) to a component (YPbPr) and/or RGB signal (3 RCA-style cables). You'd use one of these when you have to get a VGA signal into an RGB or YPbPr display device that does not accept a PC VGA signal (or vice versa). But good ones will probably cost $100 or more.

    By the way, I've never, ever seen a laptop or non-pro (i.e., video editing rig) desktop which could put out RGB or YPbPr without some kind of add-on proprietary or powered 3rd party dongle.

    And FYI, YPbPr (aka component video found on the back of many DVD players) ≠ RGB. But note that the connector colors on component (YPbPr) outputs will be colored red-green-blue simply for convenience, and does imply that the device necessarily supports actual RGB.

    "YPbPr" aka "Component" video is luma signal plus two chroma signals - no color until added together.
    "RGB" is full-field red, plus full-field green, plus full-field blue.
    Many better projectors will accept both YPbPr and RGB, but I'd say most consumer-grade projectors are strictly YPbPr component.
  6. kcotton222 thread starter macrumors newbie

    May 8, 2009
    You're right neither solution worked. I sent back the cable and Best Buy took back the RGB switcher and apple exchanged the DVI adapter for the VGA.
    So I only lost shipping cost on the cable ($5).

    I actually found a VGA Male to DVI-I Dual Link Female Adapter at work and tried it, and you're right the trans coder is necessary. I had to try.

    Many lessons learned here for me.

    Thanks for your help with this. I appreciate your knowledge and time.
  7. kcotton222 thread starter macrumors newbie

    May 8, 2009
    Ok..this is too funny. After returning all the items, The IT guy at work randomly just brought to me a (DVI-D Dual Link to RGB cable). Exactly like the one I had except DVI-D, not DVI-I.

    If I use the Apple MP to DVI-D adapter with this cable...will the video signal work???
  8. KnightWRX macrumors Pentium


    Jan 28, 2009
    Quebec, Canada
    If it's dual link, you'll need the MDP to Dual link DVI-D which is 100$. A VGA cable is MUCH MUCH cheaper.

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