On my MBP (13-inch, Mid 2012), I note that the "fan" starts regularly for very little. Could anyone be able to tell me why is it the case and what can I do to fix it?

I know if the fan starts it is because the temperature is to height, but I don't know what to do to decrease the temperature when I work on my computer.

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That last picture comes from the SMCfanControl application. Is it normal?

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    It looks like you're using a lot of your CPU. This will heat up your computer. VMs generally use a lot of CPU power, and therefore heat up the computer, kicking the fans into action. Try turning off your VM and your temperature and fan speed will drop. Lower CPU usage = lower temps = lower fan speeds – NoahL Nov 1 '16 at 3:42
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    You never want your CPU above ~96 degrees Celsius. Your computer will try to keep your CPU lower, around 50 degrees. – NoahL Nov 1 '16 at 3:43
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    NoahL is correct: your fans are turning on because your computer is hot, your computer is hot because you're using lots of CPU power, and you're using lots of CPU power because you're running a virtual machine in VirtualBox. Anything you can do to limit your use of a VM (suspending it when not active, quitting VirtualBox when not in use, etc.) will help mitigate the problem, but otherwise I don't think there's anything you can do. – Timothy Mueller-Harder Nov 1 '16 at 5:11
  • Yes, it's VirtualBox. I run Parallels and VMware Fusion (other virtualization programs) on my MacBook Air and it pegs the CPU and drives the fan up too. Just close VirtualBox when you're not using it. – SamAndrew81 Nov 1 '16 at 17:34

Open Activity Monitor and check the "Energy" tab. Click on "Energy Impact" to see what is using the most energy. This is likely what is causing the heat. Close this program when not in use. You can monitor the temp with Temperature Monitor (built into OS X). Spotlight > Temperature Monitor

Also, this 3rd party program can help, SMCfanControl: https://www.eidac.de

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    I added some more information for you. – Sandra Ross Nov 1 '16 at 0:55
  • What does the SMCfanControl is supposed to do exactly? Because the fan is stopping right now, and I don't even know if it is a good thing. – Sandra Ross Nov 1 '16 at 1:20
  • SMCfanControl just monitors the fan and can turn it up for you manually (to cool down the Mac). – SamAndrew81 Nov 1 '16 at 17:31

One thing you can try is resetting the SMC.

Since your MacBook Pro has a built-in battery, here’s what you do:

  1. Shut down your computer
  2. Keep the MagSafe adapter (or power cable) plugged in.
  3. Press at the same time shiftcontroloption (on the left side of the keyboard) and the power button
  4. Let go
  5. Turn your computer back on with the power button.

Hope this helps. Let us know how you go.

  • Sorry, I've tried your suggestion, but it doesn't work – Sandra Ross Nov 1 '16 at 1:03
  • In what sense do you mean it doesn't work? Actually, come to think of it, it's not very clear from your question what the problem is? Can you clarify what it is that's concerning you? Computer fans are designed to run when necessary, and your question says (if I understand it correctly) that they come on for short periods of time. Is that correct? If so, is there a reason why this concerns you (e.g. the computer fans are suddenly behaving differently to how they've always behaved)? I see you're also running a VirtualBox, have you always run that or is that only a recent activity? – Monomeeth Nov 1 '16 at 3:48
  • @SandraRoss the problem is not the fans running high, it's that the computer is using so much CPU, its heating up and the fans are speeding up. Look at the pic with the temp and fan speed. Temp is almost 70 C. Any computer with that CPU temp is going to be running higher than normal fan RPMs. The way to slow down the fans is to use less CPU-intensive processes. I bet quitting VirtualBox VM would lower the fan speed almost instantly – NoahL Nov 1 '16 at 5:14
  • @NoahL Ok, but at 67 degrees I wouldn't be at all worried. The OP, however, seems quite stressed about it. I'm just wondering if their concern is more about the fans whirring away and making noise rather than anything else? I guess my point is, if it weren't for the fans, would there have been any other symptoms that concerned the OP (e.g. crashes, sluggish response times, spinning beach ball, etc)? If the fans are only coming on for short periods, why be worried about it? This resource - which can be filtered - clearly shows 69 degrees is nothing unusual. – Monomeeth Nov 1 '16 at 6:15
  • On my MBP, I regularly have fans speeding up to 6000 RPM based on CPU usage. Unless you are experiencing other symptoms, @SandraRoss, I don't think you should be worried about it. It's just normal behavior. – NoahL Nov 1 '16 at 6:18

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