Retina MacBook Pro 15 Clamshell Heat Issue?

Discussion in 'MacBook Pro' started by jfriedman8, Apr 10, 2013.

  1. jfriedman8 macrumors 6502

    Feb 8, 2008
    I've just started using my MBP in clamshell mode with my Samsung PLS display and noticed that even in light tasks, the MBPr is getting warm/hot, and I can hear the fans going. I can upload a pic of the way its set up, but there is ventilation. Any suggestions from other users doing this to keep from overheating and killing the machine?
  2. justperry macrumors G3


    Aug 10, 2007
    In the core of a black hole.
    Buy a small fan like this one, cheap and works well:

  3. tekksan macrumors regular

    Mar 27, 2009
  4. inlinevolvo macrumors 6502

    Jul 11, 2012
    Overheating? Has it shut down? No? It's not overheating. The fans are meant to ramp up to cool the system. I'm not sure how you can physically stop a chip from generating heat.
  5. Brian Y macrumors 68040

    Oct 21, 2012
    It will naturally get hotter in clamshell mode since there's less ventilation. However, the fans will automatically spin up to compensate if it gets hot.

    It wont overheat until it reaches 100ºC at the CPU die, at which point it will shut itself down.
  6. inlinevolvo macrumors 6502

    Jul 11, 2012
    Less ventilation? Closing the lid doesn't block any of the air vents.
  7. GGJstudios macrumors Westmere


    May 16, 2008
    There is no ventilation impairment by closing the lid, as the vents are in the rear, near the hinge.
    It can actually go higher than that. The Intel processors used in Macs are designed to automatically shut down to prevent damage if they truly overheat. CPU Tjmax = 105C (221F), GPU Tjmax = 100C (212F) on i3, i5, i7 processors. (Source: Intel)
    Running in clamshell will not damage your Mac. They're designed for that.
  8. Rocketpaul macrumors regular

    Aug 3, 2012
    That is unusual , when i run my external monitor with clamshell mode my macbook is the coolest it ever gets, probably due to the fewer pixels.
  9. Brian Y macrumors 68040

    Oct 21, 2012
    No, but put your fingers on the aluminium between the on the keyboard. The top case acts as a giant heatsink and dissipates heat. Closing the lid will marginally affect this dissipation.

    Cooling is about more than air vents.


    Again, see above. Cooling isn't limited to air vents.
  10. inlinevolvo macrumors 6502

    Jul 11, 2012
    Thank you for your explanation of how cooling works. My point was closing the lid doesn't affect ventilation, as the lid does not block the air vents.

    Arguably, the closed screen too acts as a heat sink as it too is made of aluminum.
  11. GGJstudios macrumors Westmere


    May 16, 2008
    The reduction in heat dissipation in clamshell mode is very minor, affecting temps by only a few degrees. There is no risk in using clamshell mode, as Mac notebooks are specifically designed for that.
  12. duervo, Apr 11, 2013
    Last edited: Apr 11, 2013

    duervo macrumors 68020


    Feb 5, 2011
    The case does not act as a heatsink. It acts more like an insulator. Heatsinks require direct contact with the component they are cooling. The more thorough the contact is, the better the cooling is, up to a certain point (this is where thermal paste comes in, and once its limits are reached, liquid cooling comes into play, etc.)

    A laptop's casing will more closely resemble an insulator than a heat sink. There is not a whole lot of direct contact between the CPU/GPU and the case. Think of a stainless steel coffee travel mug. The air in between the layers of steel insulates the liquid inside, keeping hot drinks warmer for longer periods, and cold drinks cooler for longer periods. The same principal applies to these laptops.

    If you want your system to stay cool when the display is closed, then make sure the fan intakes and exhaust are free of obstruction for at least a 2 inch gap away from them.

    Some would theorize that the spaces between the keys in the keyboard allow heat to escape, thereby giving the laptop more cooling ability. Such ability would be diminished by having the display closed over the keyboard. IMHO, that theory is more believable to me than the case acting as a heat sink.

    For the OP: When you attach an external display to your system, it engages the dedicated GPU in the system. I suspect that having the dedicated GPU on all the time to drive the external display is the biggest cause for your increased temps.
  13. GGJstudios macrumors Westmere


    May 16, 2008
    Such a theory is not informed, as there is a solid panel under the keyboard, preventing any venting and minimizing any difference in dissipation between any areas of the keyboard. The fact remains that Mac notebooks do not rely on the lid being open for effective cooling.
  14. Brian Y macrumors 68040

    Oct 21, 2012
    Well if it affects temps by a few degrees then it has an effect? You're contradicting yourself.
  15. w00t951 macrumors 68000


    Jan 6, 2009
    Pittsburgh, PA
    At least for a 2011 MacBook Pro, I can say that there is definitely say that there is throttling with clamshell gaming. I recently bought an IPS monitor (best I've ever found, BTW), and I thought I could play Battlefield 3 with the lid down.

    My frames dropped to ~15 from my previous of 45-60, and I couldn't figure out why. I opened the lid and was greeted by a wave of heat. The fans might not be obstructed, but heat tends to rise, and blocking the keyboard with the display will prevent heat from dissipating under extreme system load. The result? Extreme thermal throttling.

    EDIT: After opening, my frames quickly returned to their norm after a few minutes of cooling. Everything's good now - I just have to leave the lid open when playing demanding games.
  16. GGJstudios macrumors Westmere


    May 16, 2008
    I'm not contradicting myself. I never said it had no effect. I said any reduction in dissipation is very minor. It will not affect safe operation.
  17. donpromillo macrumors newbie

    Oct 28, 2013
    effect on the display?

    Might the closed lid has some effect on the retina display? I mean when the display is exposed to the warm air under the lid?

  18. GGJstudios macrumors Westmere


    May 16, 2008
    No, it won't hurt it.

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