The temperatures on my CPU cores spike up for no reason sometimes. This bumps my fan speeds to run near 6000 rpm, which is extremely loud. I know this is not normal because my previous Retina MacBook Pro, early 2013 never ran at this high fan speed, even when the processor had a greater load to process and more memory was used.

Does anyone else have this problem?

temperature and fan speed reading

  • 1
    Those temperatures don't look ridiculous at all. I expect many loaded systems to reach nearly 212 or 100°C during routine operations as that's what Intel designed them to do. What CPU use is driving the system to schedule that much heat generation? Have you looked into Activity Monitor or perhaps the energy usage view in Mavericks?
    – bmike
    Dec 27, 2013 at 14:40
  • You're right. I just confirmed that it is within operating temperature. However, sometimes I am only running Google Chrome and the heat spontaneously climbs up... I am pretty sure this is a Mavericks issue because my previous macbook on Mountain Lion did not have CPU temp this high even when running 5x the amount of applications. Dec 28, 2013 at 10:38
  • 1
    @bmike The thermal threshold of Intel's cores rest at 100-105°C. That certainly doesn't mean they are designed to operate at those temperatures. It simply means they can. Skirting thermal failure is not "within spec" and SpikyDurian is hitting that. Apple didn't design their notebooks to run with fans at full speed; that should be the clearest indicator that something is awry. With that said, SpikyDurian, you should be looking into Activity Monitor, as any errand process will show up there. Monitoring fan speed and hardware is not what you want to be looking at.
    – user10355
    Jan 27, 2014 at 8:39
  • The fan speed is a symptom. The cause is an acceleration in either the central processing unit or the graphics processing unit; the two components the fans were designed to keep cool. Always look to the root of the problem, not the symptoms that undoubtedly surface. Find the process that is consuming either your CPU or GPU. My suspicions line in either kernel_task or mds, two processes known to cause problems from time to time. As I said above, consult Activity Monitor (CPU tab).
    – user10355
    Jan 27, 2014 at 8:41
  • @SpikyDurian - dumb question, but what software are you using? Jan 30, 2014 at 17:59

4 Answers 4


By default iStat Menus reads in Fahrenheit. Those are not unreasonable values for Fahrenheit. Go into the settings and switch to Celsius.


There is no way those temp are in Celsius.

Your 194 F = 94 C !

The Intel specification for maximum operating temp is 110 dgr Celsius.

Once that temp is reached the build in self protection kicks in and reduces the power.

So the CPU will self protect from melting.

However, since your fans are running at full speed, it is getting hot in there.

You might want to use the Official tools from Intel to see how your CPU is actually doing.


Hopefully you're not running a browser showing Flash video. I notice my Mac Mini and Macbook Air trigerring the fans unnecessarily when I open Youtube and other websites that use Flash. This can happen even hours after I watched the Flash video but kept that browser open.

My advice, always close those browser that opened a Flash video.


That's the same on my late 2013: when I watch youtube videos on Chrome, temp goes to almost 100°C. That doesn't happen on Safari. I changed also to HTML5 instead of Flash.


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