External monitor on integrated graphics

Discussion in 'MacBook Pro' started by STL, Mar 3, 2011.

  1. STL macrumors newbie

    Joined:
    Feb 25, 2011
    #1
    Can the 2011 15" run an external monitor using the integrated GPU, or is the discrete GPU required to run the second screen?

    Thanks!

    STL
     
  2. cupcakes2000 macrumors 6502

    Joined:
    Apr 13, 2010
    #2
    Will work one fine. My white 2006 macbook 2.16 core2duo with gma graphics runs a 24" 1920x1080 with no probs.
     
  3. simsaladimbamba

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    Nov 28, 2010
    Location:
    located
    #3
    Apple says you can:
    from http://www.apple.com/macbookpro/specs-13inch.html
     
  4. STL thread starter macrumors newbie

    Joined:
    Feb 25, 2011
    #4
    Hmmm... Mine doesn't work.

    When I hook up an external monitor, the GPU switches from internal to the discrete.

    When I manually switch it back using gfxCardStatus - the external goes blank and won't switch on for anything!

    STL
     
  5. cupcakes2000 macrumors 6502

    Joined:
    Apr 13, 2010
    #5
    That's weird! Graphics don't get any worse than the GMA 950 in my old macbook.
     
  6. STL thread starter macrumors newbie

    Joined:
    Feb 25, 2011
    #6
    Can someone with a new quad core Macbook 15" or 17" verify this? Can you run an external monitor off of the integrated GPU?

    Thanks!

    STL
     
  7. Derango macrumors regular

    Joined:
    Feb 25, 2011
    #7
    The intel GPU on the 15" cannot output stuff to the display port, only to the LCD. It's not set up to be able to do this like it is on the 13"

    The discrete graphics will trigger when you're using the display port.
     
  8. skiltrip macrumors 68030

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    May 6, 2010
    Location:
    New York
    #8
    Is there any reason someone would NOT want the AMD video card to kick in? Why does it matter? Not challenging at all, actually asking because I'm curious.
     
  9. Vantage Point macrumors 65816

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    Mar 1, 2010
    Location:
    New Jersey
    #9
    Since the 2010 MBP's the dedicated graphics chip automatically kicks in when an external monitor is connected. The same is true for certain programs. Prior to that you had to manually switch by logging off and back on which was time consuming. Automatic graphics switching has been a standard feature for a about a year
     
  10. abhic macrumors member

    Joined:
    Mar 27, 2011
    #10

    Yup, it doesn't work without Discrete or AMD exclusively selected using gfxCardStatus.

    I did think of not using it too to save on battery life, but then why use an external LCD at that time too :)
     
  11. Derango macrumors regular

    Joined:
    Feb 25, 2011
    #11
    I can also add if you forget that you've forced it to use the integrated GPU only and then try to restart in to clamshell mode with that setting still set it'll cause things to freeze up and be generally ungood until you restart your computer again without the external display and change it back to dynamic switching.

    So yeah. It's not possible.
     
  12. jon08 macrumors 68000

    Joined:
    Nov 14, 2008
    #12
    Apparently it's not possible and it's quite a disappointment. I have a Dell U2311H monitor hooked to my late-2011 15" MBP and the monitor always utilizes the dedicated GPU. Consequently, my CPU & GPU are constantly in their 60s (Celsius), with CPU often in low 70s as well. And gpxcardstatus won't work when I try to make a switch to the integrated GPU with the monitor hooked up.

    I wish I could just run my external monitor with the integrated GPU - I mean with 8GB RAM, it can utilize up to 512MB for itself so I don't think it could be a problem running a monitor??

    And I hate to have my CPU running at tems 65-75C and GPU at 60-65C all-day long just because of the damn monitor... Which then easily triggers the fans' rpm to go up.

    Just last night I tried unhooking my external monitor and CPU/GPU temps dropped by like 20C within 10mins while using the integrated GPU!

    So I guess it wouldn't be possible to power the external monitor only (and disable the MBP screen) and thus make it work with the integrated GPU?
     
  13. mape2k macrumors regular

    Joined:
    Apr 18, 2011
    Location:
    Germany
    #13
    That is not possible. The 15" and 17" will always demand dedicated graphics if you connect an external display to the MiniDP.
    You can control your fans with SMC Fan control to stop them from revving up at 60...70C.
     
  14. thundersteele macrumors 68030

    Joined:
    Oct 19, 2011
    Location:
    Switzerland
    #14
    If it were to work at all, one should first set the GPU to integrated using gfxcardstatus, then try to connect the external display.

    If the iGPU has no connection to the external port, then it is not possible. If it is software driven, then maybe it can be hacked to work in the desired way.

    Why would one want this?
    I can imagine a few situations where it would be desirable to a) minimize power consumption while using an external display (a presentation using a projector for example), and b) I also prefer my machine to be quiet when doing simple tasks.

    @jon08
    I don't hear my fans below CPU temps of 80 C. Are you using fan control to speed them up in the first place?
     
  15. mape2k macrumors regular

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    Apr 18, 2011
    Location:
    Germany
    #15
    Just tried it out. If you force integrated before connecting a monitor, it will not work when you plug it in.
     
  16. dusk007 macrumors 68040

    dusk007

    Joined:
    Dec 5, 2009
    #16
    Because the whole notebook stays a lot cooler and the Intel GPU is perfectly capable of handling two monitors with normal 2D stuff.

    Unfortunately there is no connection from the Intel GPU to anything but the integrated Panel. There is really no way to get that to work and no software update could ever change that.
    I hope they change this and with the next MacBook Pro refresh and use a software layer like Optimus and ADS instead of this multiplexing nonsense with all its downsides and more problems than benefits.
    The Intel HD 4000 will support UHD that is 4 times 1080p resolution and it would be a real waste if one has to suffer the loud fans of an active dedicated GPU just for watching a video on a second monitor and doing a bit of web browsing.
     
  17. GuitarG20 macrumors 65816

    GuitarG20

    Joined:
    Jun 3, 2011
    #18
    it is impossible to do this on a 15". The only card that has access to the TB port is the AMD dedicated card. That's the same reason why you need the AMD card enabled to do anything with the TB port.
     
  18. simsaladimbamba

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    Nov 28, 2010
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    located
    #19
    So even if I just connect one of the few storage devices using TB to my 2011 MBP, the dGPU should/will be activated?
     
  19. jon08 macrumors 68000

    Joined:
    Nov 14, 2008
    #20
    Could then utilizing the dedicated GPU every day for 8-9 hrs in order to keep my external monitor running, shorten the GPU's lifespan drastically??
     
  20. simsaladimbamba

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    #21
    No.
     
  21. VMMan macrumors 6502a

    Joined:
    Mar 29, 2009
    #22
    @OP,

    If it makes you feel any better, I tried using my MBA to drive a Dell 24" LCD but found the video to have artifacts that were bothersome enough that I went back to using my early 2011 MBP 17" to drive the external LCD. The discrete graphics in my case provided much better video playback. I am no longer disappointed that my MBP won't let me use the Intel graphics for an external monitor.
     
  22. GuitarG20 macrumors 65816

    GuitarG20

    Joined:
    Jun 3, 2011
    #23
    yes. and if you try to force dedicated, it will not let the TB port do anything.
     

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