I don't often hear my Macbook accelerate and start heating up, but today I was installing mariadb through Homebrew and it required compiling. I have a mid-2012 15" Macbook pro with a high-resolution screen (the version released alongside with the Retina Macbooks)
The charger was connected but the light was green, so the battery was done charging already. When the compiling phase began, I heard my fan rocket to a very high speed. The charger was still connected (could that have had an impact the temperature?).

When I installed smcfancontrol it registered temperatures of 100–105 °C (212-221 °F) and the fan was running at more than 6000 RPM.

Is this normal? Reading around I read mentions of the maximum temperature before heat damage occurs being 95 °C, and my Mac went well over a hundred for a few minutes.

Edit: When idle, the Macbook runs at 66 °C and 2000 RPM with the charger disconnected, and around the same temperature with it connected.

  • 2
    be sure to allow air to ventilate - it helps Sep 25, 2012 at 15:12
  • Does using a laptop stand improve ventilation?
    – kettlepot
    Sep 25, 2012 at 18:51
  • Perhaps. Note that things like video encoding which run at 100% cpu for prolonged amount of time will cause the fans to start regardless what. I would really appreciate a setting to allow throttling the cpu instead of starting the fans. Sep 25, 2012 at 18:54
  • Also note that third-party sensor readers, may decode incorrectly. Always double check. Jan 20, 2020 at 21:22

1 Answer 1


Yes this is normal, Intel lists a "Thermal Junction" for the Intel® Core™ i7-3615QM Processor (6M Cache, up to 3.30 GHz) at 105 Degrees Celsius. This CPU information is referenced from details in EveryMacs' Apple MacBook Pro "Core i7" 2.3 15" Mid-2012 Specs. Modern CPUs pretty much detect when there is a temperature problem and will shutdown if it detects that its overheating.

Large Compiling tasks can take the CPU to its limits, which is causing your MacBook Pro to have to dissipate way more heat that it does normally, hence why its hot and blaring its fans to keep it from overheating. This happens pretty much across the board with most Apple laptops when you push the CPU's to 100% for an extended period of time.

Ear plugs, a laptop stand, headphones, or a Mac Pro desktop (with whisper quiet fans) may be good accessories if you plan on compiling a lot of software packages on a regular basis.

  • Does "Thermal Junction" mean its maximum temperature? If so, I've seen it hit about that when rendering video. Should it hit its maximum? Can that damage the CPU?
    – Jowie
    Mar 17, 2013 at 17:28
  • Just wondering, is it still normal for it to reach 85-95 °C while idle with the charger attached?
    – kettlepot
    Aug 4, 2013 at 15:44
  • Its almost 10 years passed after last comment, I am sitting in an air conditioned room with temperature of around 25 deg celcius, I still see MacBook air reaching 105 degree celsius, when compilation is going on May 3, 2023 at 7:24
  • @AkshayVijayJain all that can be said at this point is this via song youtube.com/watch?v=bO4HnZ7XLsU&t=68s
    – MrDaniel
    May 10, 2023 at 17:57

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