15" rmbp + 750M running really hot with 2 external displays

Discussion in 'MacBook Pro' started by commac, Dec 4, 2013.

  1. commac macrumors regular

    Nov 1, 2013
    I am running 2 22" 1680x1050 and the retina display. One via minidisplay to dvi and the other hmi to dvi. The 15" + 750M gets uncomfortably hot near the Fkeys. Makes me uneasy going clamshell as the heat could burn the retina screen....

    Would a thunderbolt display run cooler? How about 2 thunderbolts daisy chained to the same thunderbolt port?

    Also, wondering if the iGPU version would run much cooler running 2 displays without losing performance?
  2. durkkin macrumors regular

    Sep 23, 2013
    Well your GPU is pushing more than 8.5 million pixels, so yeah, it's going to generate some heat. The iGPU *might* be able to handle that, but it's definitely going to have worse performance. A Thunderbolt display is 2560x1440, so that's even more pixels to generate which is even more heat. The connector type isn't going to have any effect on heat dissipation...
  3. commac thread starter macrumors regular

    Nov 1, 2013
    I understood the thunderbolt displays have their own components that could theoretically take some of the load off the computer powering them.
  4. FrozenDarkness macrumors 65816

    Mar 21, 2009
    i'm not really sure it's a worry that the heat would fry your display, but i mean what are you running on these screens? can you check your CPU/GPU usage %?

    I"m pushing a clamshell, and 2 thunderbolt displays and my coworker is pushing the clamshell and a 30" which is theoretically more pixels than your 2 22" and we're all fine
  5. commac thread starter macrumors regular

    Nov 1, 2013
    I will check tonight. What model are you running?
  6. eagandale4114 macrumors 65816


    May 20, 2011
    The displays don't have any sort of internal processors that could help. All the computation will be done on your mac. It will get warm.
  7. goMac macrumors 603

    Apr 15, 2004
    They do not.
  8. mrsavage1 macrumors regular

    Feb 1, 2010
    I would really like to know if the iGPU doesn't turn on the fans too much with 2 displays but i can't get any answer on the site.
  9. commac, Dec 4, 2013
    Last edited: Dec 4, 2013

    commac thread starter macrumors regular

    Nov 1, 2013
    I tried my setup in clamshell and the computer runs silent and cool. But as soon as I open up the retina display it starts to boil. No fan which is strange but very noticeably hot to the touch by the FKeys.

    I wonder if your machine would blowup if you tried running the double thunder with the retina lid open?
  10. Mattstrete macrumors member

    Nov 14, 2011
    I run two TBDs with my early 2013 rMBP. The mac runs much hotter when running all three displays (i.e. the two TBDs and the retina display) than when running only the TBDs (in clamshell mode).
  11. commac thread starter macrumors regular

    Nov 1, 2013
    This is indeed a good question. Anyone care to share? Would the HD5200 be as competent as the 750M pushing multiple displays running adobe software? Maybe run cooler?
  12. dusk007 macrumors 68040


    Dec 5, 2009
    Shouldn't be a problem.

    For 2D stuff there is plenty of ROP performance. These GPUs can push enough pixels to handle two 4k displays. Some comparatively low resolution Thunderbolt Displays won't make them sweat.

    ad Retina+TBD. I think there is some issues with HiDPI mode. Running some displays in HiDPI and others not may be what is causing the performance issues. I only have the 750M available externally and it is no different. I doubt there is any noticable difference in resolution handling capability between a 750M and an Iris Pro.
    In theory both have plenty of room for 2 extra displays.

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