Does Mini displayport A/B Switch (not KVM) Exist?

Discussion in 'Mac Accessories' started by xyzzy-xyzzy, Jan 21, 2011.

  1. xyzzy-xyzzy macrumors member

    Sep 19, 2010
    On my 2010 mac pro I have a 5870 video card with of its mini displayports (mDP's) driving a 27" ACD and a VGA monitor. I want a switch so that I can connect one of the mDP's to either the VGA or an HDTV. Basically an "A/B switch". Currently the only way I can do this is manually by unplugging the VGA and plugging in the HDTV and vice versa. Over time this can be a little hard on the connectors so a switch would be nice. But does such a switch exist?

    I've done a lot of google searches but turned up nothing. One search turned up the Atlona AT-MDP21 KVM which I thought maybe I could run in "reverse" but a quick call to Atlona tech support killed that idea. So I'm wondering if anyone has any ideas.
  2. waw74, Jan 21, 2011
    Last edited: Jan 21, 2011

    waw74 macrumors 68030

    May 27, 2008

    1 ---- ACD

    2a -----VGA --- monitor (using MDP to VGA adapter)
    b ------?? ----- HDTV (guessing you have some sort of adapter, that converts MDP to whatever is on the TV, HDMI?)

    could you just use a mini display port splitter or this one?
  3. xyzzy-xyzzy, Jan 22, 2011
    Last edited: Jan 22, 2011

    xyzzy-xyzzy thread starter macrumors member

    Sep 19, 2010
    Well, just to be clear/explicit here's your diagram modified:

    1 --- ACD

    2a --- mDP-to-VGA adapter --- VGA
    2b --- mdP-to-HDMI adapter --- HDMI cable --- Sony 32XBR6 HDTV

    I didn't mention using the appropriate adapters because I thought that would be obvious and I didn't want to detract from my basic question.

    Your links are to 1-to-2 splitters, not switches. I don't want to drive VGA and HDTV simultaneously and I don't even know what the Display preferences would make of such an attachment (i.e. it wouldn't know what it's talking to -- a 1024 x 768 VGA or a 1080p TV). I suspect the sound prefs would be equally confused.

    Now if there was a "splitter" that let you choose which of the two paths to use, that would be an "A/B switch" (using, for example, TV antenna terminology -- I use an A/B antenna switch to switch between two OTA TV antennas) and that's what I am looking for.

    On the other hand if I end up not finding a mDP A/B switch that link you gave to the TrippLite mDP splitter may be the next best thing (forget the $269 Atlona considering the TrippLite is under $40). If I have to do the switching manually I'd rather wear out the connectors in relatively cheap splitters and adapters as opposed to the mDP connectors in the expensive 5870 video card!;) Thanks for that link.

    [Now I wonder if that mDP splitter also has audio pass through -- can't tell from the specs -- I'll send Tripp Lite an email.]

    Hmm, I thought some more about what I just said about using a splitter. If I would still have use something like that and switch manually just because I'm worried about waring out the mDP connector on the video card I might just as well use an mDP extension cable since I would only be using one port of the splitter at any one time. So unless a real mDP A/B switch exists (at a reasonable price of course) I think I'll just get a mDP extension cable.
  4. mikecism macrumors newbie

    Jul 18, 2010
    The Tripp-Lite splitter does not work with Macs (at least not Macbooks; have not tested desktop.)

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