iMac and 30" Display

Discussion in 'iMac' started by joshwest, Dec 25, 2007.

  1. joshwest macrumors 65816

    joshwest

    Joined:
    Apr 27, 2005
    #1
    Hey Guys if you plug a 30" display up to a iMac do you get a poor resolution or will it not drive it whatsoever?
     
  2. eXan macrumors 601

    eXan

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    Jan 10, 2005
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    Russia
    #2
    Yes, the maximum resolution will be 1280x800, just like the screen on MacBooks :p
     
  3. wshld macrumors newbie

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    Aug 7, 2007
    #3
    Well I have a 1650x1080 resolution on my 20" external monitor.
     
  4. OhFrenchman macrumors newbie

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    Nov 21, 2007
    #4
    Seems like your irony detector isn't powered properly ;)

    With just a very quick search you (joshwest) would have found out that the maximum resolution for external monitors connected via DVI to the current aluminum iMacs is
    whereas the 30" Cinema Display is best driven by a resolution of 2560 x 1600. You'd be better of with a 23"/24" display
     
  5. eXan macrumors 601

    eXan

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    #5
    The maximum resolution you can run a 30" display connected to a non-Dual Link DVI port is 1280x800.
     
  6. Matek macrumors 6502a

    Joined:
    Jun 6, 2007
    #6
    According to this page the 30" can display 1920 x 1200 and since that's the max. resolution of a single link DVI that the MacBook supports, I can't see why one couldn't use it.
     
  7. OhFrenchman macrumors newbie

    Joined:
    Nov 21, 2007
    #7
    You of course could use it with a MacBook or iMac, but because of the higher native resolution of the 30" display the picture when driven by a lower resolution will probably be relatively poor (blurry). A 23"/24" display is a much better choice with a maximum output resolution of 1900x1200.
     
  8. netdog macrumors 603

    netdog

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    London
    #8
    1280x800 is absolutely correct despite the fact that it can run the 20" and 23" at far higher resolutions.
     
  9. eXan macrumors 601

    eXan

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    Russia
    #9
    AGAIN, the maximum resolution you can run a 30" display on a single-link DVI port is 1280x800.

    Is it really so hard to understand? :confused: :rolleyes:
     
  10. jnc macrumors 68020

    jnc

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    #10
    OhFrenchman said nothing to the contrary :p
     
  11. eXan macrumors 601

    eXan

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    #11
    He said that you can run a 30" @ up to 1920x1200 on a single-link DVI.
     
  12. jnc macrumors 68020

    jnc

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    #12
    :confused: Far as I can see, he quoted someone else who said it, but recommended getting a smaller unit that would correctly ouput the max external resolution.
     
  13. eXan macrumors 601

    eXan

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    #13
    Then you should read his second post more attentively. Especially the part where he said "Of course you can use it" refering to the possibility of using 1920x1200 on a 30" with SL DVI
     
  14. jnc macrumors 68020

    jnc

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    #14
    Perhaps you should read it LESS attentively?! All he says is "you of course could use it" - you could use it - meaning the 30" unit in general, but "the resolution it will be poor/blurry, get a smaller unit with 1900x1200 max output" [paraphrased]

    Uh oh, I'm right!
     
  15. Leon Kowalski macrumors 6502a

    Leon Kowalski

    Joined:
    Sep 20, 2007
    Location:
    Gondwanaland Reunification Front HQ
    #15
    Easy to understand the words -- difficult to understand the logic:

    - The 30" ACD specifies that it will accept a 1920 x 1200 DVI input.

    - The iMac specifies that it will drive a 1920 x 1200 x 60 Hz DVI monitor.

    - The DVI standard requires 1920 x 1200 x 60 Hz to use single-link DVI only.

    http://www.apple.com/displays/specs.html
    http://developer.apple.com/document...e_ref/doc/uid/TP40003994-DontLinkElementID_11
    http://en.wikipedia.org/wiki/DVI#Specifications


    So, what's the story? WHY doesn't 1920 x 1200 work on a 30" ACD?

    No, it won't be pretty -- but Apple's specs seem to claim it should work.

    ...just curious,

    LK
     
  16. eXan macrumors 601

    eXan

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    Russia
    #16
    Apple's claim is that to run 30" display you need a DL DVI port. They aren't saying it would work @ 1920x1200, they just say it doesn't work with anything less than DL DVI.

    Why 1280x800? I don't know, but I know its exactly 1280x800.
     
  17. Leon Kowalski macrumors 6502a

    Leon Kowalski

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    #17
    Mabe you should read up on DVI. The standard says:

    1) You MUST use dual-link at 2560 x 1600 x 60 Hz.

    2) You MUST NOT use dual-link at 1920 x 1200 x 60 Hz.

    See link above.


    No? Then WHY does the 30" ACL spec sheet say "1920 x 1200" ?

    See link above.


    WHERE does Apple say any such thing?

    URL, please.


    If it "doesn't work with anything less than DL", then it can't do 1280 x 800.

    1) The DVI standard forbids using dual-link at that resolution. See link above.

    2) The iMac has NO WAY to drive a dual-link DVI -- the mini-DVI output
    DOES NOT supply the required Link-2 RGB signals. See link below.

    http://en.wikipedia.org/wiki/Mini-DVI.


    ...BTW, large fonts are not a substitute for facts,

    LK
     
  18. netdog macrumors 603

    netdog

    Joined:
    Feb 6, 2006
    Location:
    London
    #18
    I am sitting here in front of my ACD 30" which is attached to a Mini C2D with 4GB of RAM (3.3 if you want to be technical).

    It has the same output through its single link DVI that an iMac does -- up to 1920x1200 @ 60Hz.

    It will only run this monitor at 1280x800. End of story.

    I could kill Multi for convincing me not to get my Mac Pro in August!
     
  19. Leon Kowalski macrumors 6502a

    Leon Kowalski

    Joined:
    Sep 20, 2007
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    #19
    Does this help?

    http://docs.info.apple.com/article.html?artnum=106564

    BTW, I'm not saying 1920x1200 works (I don't have a 30" ACD or
    any other 2560 x 1600 display) -- just wondering why the specs
    (on both ends of the wire) say "1920 x 1200" if it doesn't work.


    ...who/what is "Multi" ?

    LK
     
  20. eXan macrumors 601

    eXan

    Joined:
    Jan 10, 2005
    Location:
    Russia
    #20
    Not exactly. You should replace "at" with "for displays with maximum resolution"

    http://www.apple.com/displays/specs.html

    Here you go. Read the part with the words "Compatibility". It clearly states that 30" isn't compatible with computers that only have SL DVI (Mac mini, etc)

    Because when used with a compatible computer, you can run 30" at 1920x1200 resolution, or any other from the list from the link I've given above.
     
  21. Leon Kowalski macrumors 6502a

    Leon Kowalski

    Joined:
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    Gondwanaland Reunification Front HQ
    #21
    The DVI link doesn't give a rat's rump about the "maximum resolution" of
    the receiving device. DVI doesn't even care whether the receiving device
    is a display at all -- or whether 'resolution' has any meaning to the device.

    DVI cares ONLY about the bandwidth of the signal being transmitted. If
    the required bandwidth is less than 3.7 Gb/s, it MUST BE transmitted in
    single-link mode -- and the link #2 RGB signal pairs MUST NOT be used.

    "Dual link capability" has absolutely no meaning at 1920 x 1200 x 60Hz
    (3.3 Gb/s); whether it exists or not, the second link will not be used.

    http://en.wikipedia.org/wiki/DVI

    Here you go. Read the part with the words "can run." Its learned author clearly
    states that 30" is compatible with computers that only have SL DVI. Sometimes.

    http://forums.macrumors.com/showpost.php?p=4655836

    So, how is 1280x800 different from 1920x1200? They're both single-link DVI
    frequencies, and they're both listed on the iMac and 30" ACD spec sheets.


    "Few things are harder to put up with than the annoyance of a good example."
    - Mark Twain

    .
     
  22. eXan macrumors 601

    eXan

    Joined:
    Jan 10, 2005
    Location:
    Russia
    #22
    Doesn't change the fact that the SL DVI can output only 1280x800 for a 30" display.

    Yes, I said you can run a 30" display connected to a SL DVI, but the maximum resolution for it will be 1280x800.

    Yes, you CAN run it, but only at 1/4 of it's native resolution, so NO point in doing it.

    Just like, despite Apple's claim that Motion isn't compatible with integrated graphics, you CAN run it on MacBooks and Mac minis, but it's SO slow, that there's NO point in doing it.

    As I already said in this thread, I do not know why the limit is 1280x800. And I have already said why Apple has 1920x1200 in ACD's specs page.

    This is becoming rather annoying. Why continue this pointless discussion? Are you being stubborn for the sake of being stubborn? The OP has already got his answer, and that answer is confirmed by people who actually use 30" with SL DVI, like netdog
     

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