iMac (intel) to HDTV

Discussion in 'Mac Pro' started by srobert, Jan 11, 2006.

  1. srobert macrumors 68020

    srobert

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    Jan 7, 2002
    #1
    I'm wondering at what resolution (If at all) the iMac will output to my HD TV. (connecting from the mini DVI port of the iMac to the HDMI port of my TV.)

    What we know:

    • Ati Radeon X1600 supports external display in extended desktop and video mirroring modes. Digital resolutions up to 1920 x 1200 and analog resolutions up to 2045 x 1536.

    • DVI can support HDCP which is the copyright protection... Not sure if new Macs have this built in... asitcher

    • The Microsoft WMV-HD page recommends 256MB of video RAM for smooth 1080pmartinAyla

    • The X1600 (according to the ATI website) supports both HDCP (as questioned earlier) over the DVI output and it supports >hardware decoding< of MPEG-2, MPEG-4, DivX, WMV9 and VC-1 - H.264!!martinAyla

    • PS. The X1600 only supports hardware decoding at 720p max resolution but I think this is a software issue (hopefully that will change, X1800 supports 1080p).martinAyla

    I'd like to hear about 1st hand experiences.

    Anybody knows how the intel iMac will handle HD 1080p movie previews? My dual 1.8 GHZ G5 is doing OK, but not great.
     
  2. srobert thread starter macrumors 68020

    srobert

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    Jan 7, 2002
    #2
    This looks like this would be the right kind of cable for hooking the iMac to a HDTV with a HDMI port. (Male to Male, also using Mini DVI to DVI adaptor) Anybody can confirm?

    [​IMG]
     
  3. MartinAyla macrumors regular

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    Jan 10, 2006
    #3
    Hi

    Good thing you started a seperate thread srobert, hopefully we can get some of our questions answered :)

    I would like to know if the X1600 in the new iMac is just a normal X1600 like for PC's or if Apple changed anything?

    And can you do independent resolutions on your iMac screen and external monitor or does it have to be the same?

    PS. I can't see a problem with going the: iMac Mini-DVI -> DVI (to HDMI cable) -> HDTV route.

    PPS. I don't know if it's an onboard GPU. Can it be PCI Express and still be onboard, hmm, guess so?
     
  4. MartinAyla macrumors regular

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    Jan 10, 2006
    #4
    Check this thread too for a discussion about the X1600 & the iMac:
    http://forums.macrumors.com/showthread.php?p=2047562&posted=1#post2047562

    Ok, to answer some of my own questions...

    It seems from the news in the link above, that it is a "PCI-Express card" in the intel iMac, indicating that it's not just an onboard chip. But it doesn't seem like you can upgrade it later on.

    The card is the same as it's PC counterpart but it has a different firmware and drivers of course.

    X1800 on the way? Hmm don't want to buy a iMac today and miss out on a X1800 in the near future...
     
  5. srobert thread starter macrumors 68020

    srobert

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    #5
    Is there a difference between the X1600 XT and X1600 Pro? Which one is in the iMac.

    I can't seem to find a hands-on review for the X1600. All the reviews I read are from people who haven't actually used it. :-/

    To answer one of your questions MartinAyla, it looks like the X1600 can run both displays at independent resolution. (Unless Apple didn't integrate this functionality in their preference pane)

    http://www.ati.com/products/RadeonX1600/specs.html

    Some other little bits of info I dug on that page:

     
  6. powerbook911 macrumors 68040

    powerbook911

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    Mar 15, 2005
    #6
    Do you guys think we'll be able to turn off the iMac's own display and only show the external display? I'd like to use an iMac with my cinema display, but without sharing the VRAM.
     
  7. srobert thread starter macrumors 68020

    srobert

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    #7
    I don't have a real answer for you, but somehow, I don't think so. It never was an option on previous Macs. (Not that I know of)
     
  8. powerbook911 macrumors 68040

    powerbook911

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    Mar 15, 2005
    #8
    Well, you can do it on Powerbooks by shutting the lid, but I guess you're right they probably won't do it, for the iMac, you'll have to leave its display active too. I guess thats ok I can just have it display random photos, or something.

    How bad do you guys think it will hurt performance though having a second display 100 percent of the time? Not too bad, with the processor they've put in it?
     
  9. MartinAyla macrumors regular

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    Jan 10, 2006
    #9
    That shouldn't interfere with performance at all. I've never experienced that with my PC at least.

    -> srobert, sounds fantastic that you can run independent resolutions. Native on the iMac and 1024x768 native to my plasma at the same time. Hope it works :)

    PS. I have just ordered the 20" Intel iMac today (1GB RAM and 256MB VRAM). Now i just have to sleep for 10 days and it's there! :D
     
  10. MartinAyla macrumors regular

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    Jan 10, 2006
    #10
    I just read in another thread that someone saw the iMac at Macworld and it was dropping a lot of frames with 1080p. Hope that isn't true!!

    My main purpose is to watch HDTV movies. Well, I hope the hardware decoding support is there.
     
  11. srobert thread starter macrumors 68020

    srobert

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    Jan 7, 2002
    #11
    Ordered the exact same setup yesterday. I've also purchased a DVI to HDMI 12' cable confident enough now that it can work.

    By the way, I've asked a similar question on Apple support/discussion ans here is the feedback I obtained:

    I'll post my experience here as soon as it's delivered.
     
  12. Morn macrumors 6502

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    Oct 26, 2005
    #12
    Dropping frame rates with 1080p? Hmm, possible if H264. Very demanding codec, apple might have not optimised quicktime intel properly yet.
     
  13. MartinAyla macrumors regular

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    Jan 10, 2006
    #13
    This is from the MacNN forum regarding the Intel iMac:

    "First of all, the specs aren't BS. Go play with one of the machines at the expo yourself. I had 3 1080p videos playing flawlessly at once."

    "Core Duo could play one 1080p H.264 movie, maaaaaybe two on a good day, but for three they must be using the X1600 for acceleration. I'm happy to hear that Apple added support for that to the driver."

    http://forums.macnn.com/showthread.php?t=281357&page=3
     
  14. MRU macrumors demi-god

    MRU

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    Ireland
    #14
    No i think your mistaken. What you read was probably the same post I read around here. But that was with an iMac G5, not the new iMac Duo...
     
  15. Morn macrumors 6502

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    #15
    1080p h264 requires a dual system just to play..... Won't play on an imac g5 or single core PC.
     
  16. Platform macrumors 68030

    Platform

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    Dec 30, 2004
    #16
    Well it runs just fine on my iMac :D
     
  17. theBB macrumors 68020

    theBB

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    Jan 3, 2006
    #17
    My Samsung CRT HDTV has a DVI input, but the manual says it is not compatible with a computer's DVI, only with a set-top box. I thought DVI was a standard, I don't know why it would not work. It does not mention HDMI anywhere in the manual, so I don't think HDMI cable would solve my problem. (I hope somebody proves me wrong.)

    A DVI-to-component converter sounds more promising to me, although I would definitely prefer a simple DVI/HDMI route.

    This probably is not a big deal for me until (well, if) Apple starts an online video rental business that provides at least DVD quality movies. (At some point Netflix was claiming that they were working to start such a service by the end of 2006(?) I wonder what came of it. )
     
  18. howesey macrumors 6502a

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    Dec 3, 2005
    #18
    My iMac G5 rev c 20inch runs 1080p fine, I highly doubt the new iMac should have problems. I have found VLC runs a lot smoother, and also the colours are a lot better. Quicktime and DVD Player have a lot of noise, poor at upscaling, and shadows have a blue tint to them. DVD Player is one of the worst DVD player software I have ever used for image quality.
     
  19. Morn macrumors 6502

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    #19
  20. srobert thread starter macrumors 68020

    srobert

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    Jan 7, 2002
    #20
    Pretty soon I'll have my answers. My intel iMac is in transit somewhere over the pacific, on it's way from Shangai.

    Things look good after reading a first of 1st hand impressions and reviews from other threads. Looks like it can run 1080i pretty fine. Now, here's hoping that it will play nice with my TV.
     
  21. balamw Moderator

    balamw

    Staff Member

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    New England
    #21
    I think the main reason they say not to use HDMI for PC input is that they expect only 480i, 480p, 720p or 1080i coming in on the HDMI with audio and not any of the other settings that are common with a PC. i.e. HDMI only supports a small subset of what DVI supports.

    I do hope that if Apple makes a PVR-like Mini that they add an HDMI port to make things easier.

    B
     
  22. srobert thread starter macrumors 68020

    srobert

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    Jan 7, 2002
    #22
    Ok! Got the iMac. Hooked it to my TV with DVI/HDMI.

    Does it work? Well, yes and no. It dispays perfectly on the TV except for the fact that I'm missing the top and bottom of my screen on the TV. This is probably because the iMac is 16:10 and my TV is 16:9. It's not a problem when watching movies since nothing is cut, but it's inconvenient when I need to use the menu bar. Not sure if there is a way to fix this (i.e.: Have the TV scale the image down so it all fits on the screen.
     
  23. dejo Moderator

    dejo

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    #23
    srobert, have you tried changing the resolution on your "second" screen to match the aspect ratio of your HDTV?
     
  24. srobert thread starter macrumors 68020

    srobert

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    Jan 7, 2002
    #24
    By second screen you mean my iMac's display?

    Can't be done. All the available resolutions are either in the 16:10 or 4:3 aspect ration.

    Other little glitch. I just upgrade to quicktime pro but when I right click on a trailer to download it (save as quicktime movie), it only save a 4 kb picture of the clickable icon. ?


    _
     

    Attached Files:

  25. dejo Moderator

    dejo

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    #25
    You're mirroring your iMac display to the HDTV, right? Then whatever aspect ratio your iMac is at is the aspect ratio that your mirrored display will be. Darn, eh? Can you span your display across both the iMac screen and the HDTV?

    Try "Save As source..." instead? Although "Save As QuickTime Movie..." should work, unless the movie is streamed-only, such as Steve's keynotes.
     

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