Tests confirm Apple's 27" iMac only supports DisplayPort input

Posted:
in Current Mac Hardware edited January 2014
Third party testing has confirmed that Apple's new 27" iMac can only be used as an external display for devices designed to provide DisplayPort video. It will not work with any equipment that only supports VGA, DVI, or HDMI output.



In a follow-up to its teardown of the 27" iMac last week, iFixit said it revisited the new hardware to see if it could display high-definition video from a non-DisplayPort external source.



The results of the testing indicate that Apple's stated specifications for the iMac were correct; while video input worked as expected with a 13" MacBook Pro equipped with Mini DisplayPort, all attempts to use a physical adapter dongle to supply alternative video signals to the new 27" iMac failed.



"The iMac will not act as a second (or primary) display using the Mini DisplayPort to DVI adapter that Apple sells," the group's website stated. "We tried it on a PS3 Slim, as well as a MacBook and MacBook Pro. It looks like we'll have to wait for a special adapter from Apple or a third party."



A one way street



According to Apple's stated specifications however, the 27" iMac's video input feature will only ever work with DisplayPort devices, and no physical adapter will change that fact.



Apple has frequently used converter dongles on its notebooks in order to support multiple types of video output signaling via the same port. For example, previous notebook models provided Mini-DVI ports proprietary to Apple which could deliver both VGA and DVI outputs using the appropriate connector. These ports provided multiple signaling types over the same physical pins.



Apple's modern machines similarly all supply a Mini DisplayPort connector (originally designed by Apple but now part of the official DisplayPort specification); using the right connector, users can extract and output any video signal type supported by the computer, including VGA, DVI, HDMI, and DisplayPort.



VGA is analog video; DVI and HDMI are both digital, electrically compatible, serial video data formats that only differ in their physical connectors; DisplayPort is an entirely new format that uses a packet signaling format.



The iMac's Mini DisplayPort supports output of all three, but can only input and display DisplayPort video. Unlike moving from DVI to HDMI, converting a DVI signal to DisplayPort requires more than a cheap physical dongle; it would necessitate a relatively expensive converter box to process the signal into a completely new format and possibly also a scaler to match the output device to the 27" iMac's enormous resolution of 2560x1440.



This prevents the new iMac from serving as an HDTV-style output source for older DVI-based computers or HDMI-output devices such as the Playstation 3, Xbox 360, Apple TV, or standard DVD and Blu-Ray players. Future devices that support the DisplayPort standard will work, of course.



Why no DVI or HDMI input is supported



The 27" iMac's inability to input DVI video is rooted in the fact that the DisplayPort specification is uniquely designed to work as both an internal (video card to built-in display) and external (PC to monitor) video signaling system.



Non-DisplayPort systems typically use LVDS for internal video cabling and DVI for external video connectors. No Apple computers supply any sort of internal DVI input to support driving their built-in LCD via the DVI port using an external computer.



Apple's existing MacBooks, Mac mini, Mac Pro, and the smaller new 21.5" iMac model do not support video input at all. The company's 24" LED Cinema Display is the only other device that currently supports (and only supports) DisplayPort input. The 30" Cinema Display HD only supports DVI input, but not DisplayPort.



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Comments

  • Reply 1 of 149
    Apple's Mini DP to DVI adapters are one-way. But wouldn't a DVI to Mini DP adapter (like Atlona's) work? Sure isn't cheap, but I would imagine it should work..
  • Reply 2 of 149
    Quote:
    Originally Posted by blufire View Post


    Apple's Mini DP to DVI adapters are one-way. But wouldn't a DVI to Mini DP adapter (like Atlona's) work? Sure isn't cheap, but I would imagine it should work..



    This one is a little cheaper, but not by much:

    http://www.gefen.com/kvm/dproduct.jsp?prod_id=8913
  • Reply 3 of 149
    Quote:
    Originally Posted by blufire View Post


    Apple's Mini DP to DVI adapters are one-way. But wouldn't a DVI to Mini DP adapter (like Atlona's) work? Sure isn't cheap, but I would imagine it should work..



    The Altona device SHOULD work as it converts the DVI signal to a display port signal. Of course the Apple supplied adaptors don't work. I wouldn't have expected them to, as they convert the display port signal into DVI or VGA. They are not just pinout adaptors, there are electronics inside the adaptor itself.
  • Reply 4 of 149
    teckstudteckstud Posts: 6,476member
    No HDMI- No purchase of an Apple monitor with built in speakers for me.

    What device beit Blu-ray, game ,etc uses DP or MDP?

    Apple is so wrong on this. How expensive can an HDMI fee be. How much profit does Apple need?



    Oh I know , repeat after me- slopism's song - "Apple is a company that needs to................................................ .
  • Reply 5 of 149
    Since those are both active signal converters they might work, but it depends on how the iMac's display handles an unscaled, lower-resolution signal.



    I doubt the iMac has an upscaler, so it might just display 1920x1080 in a box in the center of the display, or not at all.
  • Reply 6 of 149
    sennensennen Posts: 1,468member
    Quote:
    Originally Posted by teckstud View Post


    No HDMI- No purchase of an Apple monitor with built in speakers.

    What device beit Blu-ray, game ,etc uses DP or MDP?



    man, you re so funny. everything you post is "no X, no purchase". why do you bother?



    obviously apple knows what it intends the mDP video input for, just because it doesn't match your requirements/desires doesn't mean it's broken.
  • Reply 7 of 149
    teckstudteckstud Posts: 6,476member
    All that beautiful screen wasted. No internal blu-ray, no external Blu-ray, PSP, XBOX or Wii.

    And then top it off with the VHS quality iSight camera. WTF?
  • Reply 8 of 149
    Quote:
    Originally Posted by teckstud View Post


    All that beautiful screen wasted. No internal blu-ray, no external Blu-ray, PSP, XBOX or Wii.

    And then top it off with the VHS quality iSight camera. WTF?



    VHS in an iMac? How retro.
  • Reply 9 of 149
    teckstudteckstud Posts: 6,476member
    Quote:
    Originally Posted by sennen View Post


    man, you re so funny. everything you post is "no X, no purchase". why do you bother?



    obviously apple knows what it intends the mDP video input for, just because it doesn't match your requirements/desires doesn't mean it's broken.





    Because they should get it right and just release what people want already. I had to wait 2 years to get an iPhone that was up to spec. I've been waiting 3 + years now for the same with an iMac. What good is 16:9 HD if there nothing to utilize it with. To surf the web- that 's a waste? iTunes DRM crap? Hell no.

    Ok what's it intended for today? Make me want it- go on.
  • Reply 10 of 149
    Quote:
    Originally Posted by teckstud View Post


    Ok what's it intended for today? Make me want it- go on.



    For me, it's everything I would need from a home server + an external display for my MBP.



    EDIT: Also, a friend of mine does a lot of 3D animation on his Mac Pro. He's considering an iMac to act as his display for his Mac Pro and also a headless rendering node.
  • Reply 11 of 149
    Quote:
    Originally Posted by teckstud View Post


    No HDMI- No purchase of an Apple monitor with built in speakers for me.

    What device beit Blu-ray, game ,etc uses DP or MDP?

    Apple is so wrong on this. How expensive can an HDMI fee be. How much profit does Apple need?:



    Bone up on your reading comprehension there buddy.



    The lack of HDMI input on the iMac isn't an issue with licensing fees (it has HDMI output) but rather that there's no support for driving an internal LCD display in the HDMI spec. Apple could have added entirely separate circuitry for using the display as a DVI monitor, but that would have added significantly to the cost without being a major feature. And the point of the new iMacs is to deliver the lowest cost, premium machine possible.



    And really, how many people really want to use their iMac as a TV display for their PS3? Among other problems, the resolution isn't right. A typical PS3/BR/DVD only scales to 1080, so it would only present your game or movie in the middle of the screen surrounded by lots of dead pixels.



    It does however make a lot of sense to allow the mega-screen iMac HD2 resolution available for use as a secondary display if you have a modern notebook capable of driving it, and particularly as an option for recycling the display after the computer becomes outdated in a few years.
  • Reply 12 of 149
    teckstudteckstud Posts: 6,476member
    Quote:
    Originally Posted by mariofreak85 View Post


    VHS in an iMac? How retro.



    Have you used the iSight camera on an iMac? The quality is bad, real bad. And on a 27"HD 16:9 display I can only imagine.
  • Reply 13 of 149
    Quote:
    Originally Posted by teckstud View Post


    Because they should get it right and just release what people want already. I had to wait 2 years to get an iPhone that was up to spec. I've been waiting 3 + years now for the same with an iMac. What good is 16:9 HD if there nothing to utilize it with. To surf the web- that 's a waste? iTunes DRM crap? Hell no.

    Ok what's it intended for today? Make me want it- go on.



    Take a hint. Apple doesn't want you to use their products. Why don't you move on to products that give you what you want and stop wasting disk space here.
  • Reply 14 of 149
    teckstudteckstud Posts: 6,476member
    Quote:
    Originally Posted by mariofreak85 View Post


    For me, it's everything I would need from a home server + an external display for my MBP.



    EDIT: Also, a friend of mine does a lot of 3D animation on his Mac Pro. He's considering an iMac to act as his display for his Mac Pro and also a headless rendering node.



    OK, so more like a regular computer monitor. But this is where Apple sends mixed messages. The iMac has always been a consumer not Pro machine. And the Vesa mount is too hang it - you would hang a computer work monitor? Or hang a monitor to watch movies, play games, etc? It seems like they can't make up their mind what they want it to be?
  • Reply 15 of 149
    sennensennen Posts: 1,468member
    Quote:
    Originally Posted by anilsudhakaran View Post


    Take a hint. Apple doesn't want you to use their products. Why don't you move on to products that give you what you want and stop wasting disk space here.



    quoted for truth.
  • Reply 16 of 149
    teckstudteckstud Posts: 6,476member
    Quote:
    Originally Posted by anilsudhakaran View Post


    Take a hint. Apple doesn't want you to use their products. Why don't you move on to products that give you what you want and stop wasting disk space here.



    Why don't you learn how to discuss things properly or learn how to use the ignore list? And why would Apple ever have you speak for them?
  • Reply 17 of 149
    teckstudteckstud Posts: 6,476member
    Quote:
    Originally Posted by sennen View Post


    quoted for truth.



    Repeated like a drone.
  • Reply 18 of 149
    Quote:
    Originally Posted by teckstud View Post


    OK, so more like a regular computer monitor. But this is where Apple sends mixed messages. The iMac has always been a consumer not Pro machine. And the Vesa mount is too hang it - you would hang a computer work monitor? Or hang a monitor to watch movies, play games, etc? It seems like they can't make up their mind what they want it to be?



    Actually, all the monitors at my work are mounted on movable VESA mounts. Makes adjusting them super simple, and gets them up off the desk.
  • Reply 19 of 149
    Based on the display prices I wonder if Apple could seamlessly connect two iMacs together. Two screens with the computers acting as one. How sweet! At work you could have one running windows and the other one running OS X. CTRL-ALT-DEL and your screens switch OSs or integrate the two with Parallels. That would be a smoking hot home computer too instead of a MacPro. They sell twice as many machines.
  • Reply 20 of 149
    sennensennen Posts: 1,468member
    Quote:
    Originally Posted by teckstud View Post


    Repeated like a drone.



    coming from Mr "no X, no purchase" in every thread.
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