MacBook Pro Heat Dissipation & Cooling

Discussion in 'MacBook Pro' started by NODEraser, Jun 22, 2008.

  1. NODEraser macrumors newbie


    Jun 21, 2008
    Astoria, Oregon
    I'd heard stories about the MacBook Pro running pretty hot, since the aluminum construction basically makes the entire case surface a giant heatsync. So, when I got mine recently and noticed that it does run pretty hot, I went on eBay and bought one of those cheapy USB-powered laptop cooling pads. I staged a little test, and ran the laptop for 30 minutes each on the cooler, and one the bare tabletop. Using a handy little application called "Hardware Monitor", I pulled up a graph of the various temperature sensors. Much to my surprise, running the laptop on the cooler yielded higher temperatures on the CPU, GPU and enclosure. Leaving the laptop on a bare surface lowered the temperatures by about 5 degrees.

    While by no means a scientific study, it would appear that the aluminum case works better with a solid object to conduct heat to, than with the convection-cooling that a laptop cooler provides. Of course, the cooler I used (being a cheapy made in China cooler with poorly translated packaging) was plastic, though I have my doubts that a metal cooler of the traditional design would be any better. I think it would have to be more like an external heatsync, with fans blowing across fins, rather than the type that just blows/sucks air underneath the laptop.

    The reason I even bothered with all of this, is that I was originally going to purchase a set of "Apeelz" or some other similar protective skin to keep my prized posession from getting all scratched up, or just generally icky. This test suggests that I shouldn't, and that others should think twice about enclosing their MBP/PowerBook in a plastic skin. The likely result, is that you'll just suffocate it, since the metal case already provides sufficient cooling. It would be interesting to run such a comparison with a MacBook/iBook, since its plastic construction would conduct less heat.

    Just my thoughts; wanted to see if anyone else has come to similar conclusions.
  2. Michael CM1 macrumors 603

    Feb 4, 2008
    Aside from maybe the little bar above the keyboard, the MBP gets no hotter than any other notebook I have owned. In fact, the HP I owned had a spot on the bottom that was darn near nuclear if you touched it.

    Apple recommends putting their notebooks on flat surfaces because they're designed to cool best that way. Despite the old term "laptop," these things aren't really made to be put on your lap. You can do it, but it's just not what they were made for. That's why all of these type computers are now called "notebook PCs."

    FYI, your MBP will cool best if the display is open. The keyboard is one big vent. Aluminum is one of the best metals for dissipating heat, which is why many good computer cases are made from it. The most important thing is keeping the inner components cool, not the exterior (even on a laptop).
  3. Eddyisgreat macrumors 601

    Oct 24, 2007
    The macbook Pros critical heat generating components (CPU, GPU, etc) are located around the upper half of the keyboard, with heat pipes running from the components to heatsinks located near your fans, as indicated.



    (jacked from ifixit)

    If the fans are running adequately, and Apple has correctly applied thermal grease onto your sinks (which isn't always the case), the design, even with a case, should be fine. HDD heat is negligible (in my opinion) and the other side is just a disk drive.

    What are you using to back up this reasoning?
  4. octagon macrumors newbie

    Jun 7, 2008
  5. Radio Monk33 macrumors 6502

    Dec 4, 2007
    "Originally Posted by Michael CM1
    FYI, your MBP will cool best if the display is open. The keyboard is one big vent.

    What are you using to back up this reasoning?"

    Well, having more surface area exposed with everything open certainly isn't going to make the laptop run hotter.:rolleyes: I'd be wary about running in clamshell mode while doing intensive work over a long period of time.

    As for the inside being cool being more important than the outside, if the outside is cooled, it will draw heat away from the inside so there should be some cooling effect achieved. Afterall the heat will try to distribute evenly, and if you're pulling it away from the outside, there should be some small effect on the inside.
  6. NODEraser thread starter macrumors newbie


    Jun 21, 2008
    Astoria, Oregon
    To establish a baseline with the temperatures, leaving it on the desktop yields temps of roughly 165F CPU and 175F GPU. The "Enclosure Bottomside" sensor reports 93F. The only thing that seems to vary is the wireless module, not sure why. This is while running BOINC on 1/2 cores; had a P4 notebook before and ran on both software cores (thus 100% CPU useage 24/7) and it only lasted about six months before melting down. Ever since I got the warranty replacement on that one (hehe) I've been hesitant to run any notebook at full CPU.

    I'd be interested to hear how your aluminum cooler works out; hopefully it will be better than my cheapy plastic one, but I still don't think it will help that much. From the picture you provided, it looks like another convection cooler; I think the best cooler for an MBP would be a solid block of aluminum (no convection around the case) with fins on the bottom, and fans blowing the air across these.

    Maybe after all this, I should start building custom conduction/convection coolers for MBPs!
  7. aquajet macrumors 68020

    Feb 12, 2005
    I've always noticed that the top case is pretty much the coolest part of the computer's exterior, aside from the display.

    I've used my MBP in clamshell mode many times for extended periods. This is a feature which Apple specifically designed into the both the MB and MBP. There's no reason to think that there is a problem. Let's keep FUD out of this.
  8. NODEraser thread starter macrumors newbie


    Jun 21, 2008
    Astoria, Oregon
    Does anyone happen to know the "normal" operating temperatures? I know the thermal paste application has been sub-par on some MBPs; I doubt mine is because even with all the stuff I run it hasn't been too hot to the touch--but it would be good info to have.
  9. Michael CM1 macrumors 603

    Feb 4, 2008
    I do almost everything in clamshell mode, so I'm really careful to give it the best venting possible. I use HandBrake like a MoFo, and on occasion I'll slightly open the display to let it vent a little more. It sits on a hard surface with nothing blocking the sides, so I think I've got it covered. I've been doing this for a year and haven't had any issues.

    As far as what evidence do I have of opening the displaying making the inside cooler, all I have is common sense. If something is blowing hot air away from something, it's better to have more ways for that air to leave.
  10. magiic macrumors regular


    Jun 17, 2008
    I was hoping to run my pro when I get it in clamshell mode on my desk and hook it up to my lcd monitor. This thread is making that seem like a bad idea. Is there any solution to this?
  11. Eddyisgreat macrumors 601

    Oct 24, 2007
    The sides?

    The sides have nothing to do with anything.

    The only components that will generate any real heat, and thus are coupled with thermometers on and in the adjacent area (with the exception of the airport card, which I'm not sure where it is), are the CPU, the GPU, and the Northbridge (maybe. Some of you laptop extremists can help me out). Anywho, I would guess that any extreme temperature fluctuations on the outside / sides of the computer would be due to external factors (room temp) vs. any activity from the computer.

    As far as I know, the macbook pro does not vent from the express card slot :D

    The construction of heat pipes are already doing the job you describe, and if the fans are blowing correctly, they will be extremely effective at what they do.

    EiGs summary of Macbook Pro cooling in 'Clamshell' mode:
    If your fans are working correctly, there is absolutely no danger and negligible benefit to operating your macbook pro under any conditions , period. The quick nature of the heat pipes will transfer the heat to the heatsinks quickly and efficiently enough for the fans to do their job and cool them down. If the bar at the top is "too hot to handle", either the temperatures are within acceptable range set fourth by apple (and yes, components can take some considerable load), the thermal grease facilitating the contact between the cores and the thermal pad are inadequate , insufficient or overdone (which is noted on first and second gen MBP, but are said to be fixed in rev 3) , or (finally) the fans are not doing their job , which is an isolated issue.
    The heat generated by the "main" components is taken care of via this combo whilst the heat generated by everything else in the machine is negligible, if non existent, based on external factors, and if operating correctly, provides sufficient and admirable cooling.

    Common sense gets thrown out the window and is replaced with logic and facts in an academic setting , which is my approach.

    -Typed on my closed-lid macbook pro.

    BTW: Not knocking anyones methods , because obviously they work for them. It would be wise to do your own research and come up to your own conclusions if you have any doubts.
  12. soenage macrumors newbie

    Aug 4, 2009

    And experience will throw logic out the window :)

    I couldn't resist replying to share my own experience with the macbook pro closed.

    To give you an idea of my environment, I use the CS4 design suite extensively for long hours and play games on a daily basis.

    I hooked my 1 yr. old 15" macbook pro to a 37" samsung lcd and work with my laptop closed most of the time with no problems.

    I have been doing this for about 2 months now, until recently when I started playing games with the lid closed I got the dreaded "Rapid Random Shutdown Syndrome" (aka RSS) that is prone to over-heated macbooks.

    When it first shutdown due to heat with the lid closed I thought it was just a fluke and kept playing games until it kept shutting down on me each and every time.

    Now I play with the clamshell open (minus the full resolution, oh well) while hooked up to my tv and no more shutdowns thus far.

    And I am typing this with the lid open :)
  13. adamk77 macrumors 6502

    Jan 6, 2008
    Yeah, it makes sense.

    My laptop is at its coolest when placed on top of a coffee table I have that is made of metal. The entire coffee table acts like a heat sink.
  14. Eddyisgreat macrumors 601

    Oct 24, 2007
    This thread is over a year old, but whatever.

    Like I said, if it works or doesn't work for you, great.

    But if legitimate problems arise from a users use of clamshell mode during any process then Apple has some explaining to do as it is a sanctioned and advertised feature of the entire MBP line. That's all.

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