For a few days I'm noticing the fans spinning wildly and the CPU temperature is around 65C.. I'm only doing normal browsing and the fans are at 6000RPM. Quite strange.

I have MacBook Pro mid 2010 model. I have tried to reset the SMC by holding shift+ctrl+alt+power.

It happens in OSX and in Win7 (Bootcamp).

The outside temperature in the past few days is around 33C which is a lot more than usual (summer is here:).. but still it's weird because this could only affect Mac running a bit hotter and not fan speeds being higher at some given temperature.

Sensor being faulty or fan being clogged up also can't be a reason.. only thing I see that could cause this is some fault in the controlling logic but SMC reset should have taken care of this...

Any ideas? Hmm now when the computer is completely idle the temperature shows 63C and the fans are at 3500RPM - so only a small temperature difference and 2500RPM difference in fan speed... :S The whole thing is strange.

thank you! david

  • 1
    Open up Activity Monitor and look for a process using most of your processor. Heat is a factor of CPU usage. The higher the usage, the greater the heat, the higher the fans run.
    – user10355
    Jun 20, 2013 at 23:39
  • yes... but the processor is almost not used...when browsing Chrome the cpu is at most 2-3%... also as I wrote if the temperature is 60C then the fan speed is dependent only on this, no matter what the CPU usage (it's already calculated in the temperature)
    – davidhq
    Jun 21, 2013 at 9:47
  • It's a hardware fault then. It could be a warped heat sink or perhaps an issue with the logicboard. I would advise you to take it to Apple for a diagnostic.
    – user10355
    Jun 21, 2013 at 14:27

2 Answers 2


If you are confident with opening the case of your machine and blowing some canned air at it, this is said to take care of the dust accumulation that can cause overheating. Certainly no harm in it.


While I'm not sure why this may be happening, I have a solution: smcFanControl. It's a little program that sits in your menu bar and lets you directly control the fan speed. OS X will override it when your machine gets too hot, so there's no danger in setting the speed to the minimum.

I also have a mid-2010 Macbook Pro and have been running the program since I got it.

Some pictures:

smcFanControl in the Menu Bar

smcFanControl Preferences

Pretty straightforward and simple.

  • It should be noted that it is not Apple approved product. One would believe that Apple designed its fan speed controll for a purpose so reducing it might create unwanted effects.
    – Ruskes
    Jun 20, 2013 at 23:30
  • Perchance, but I've been running it for the past three years and haven't had any problems. Also, there doesn't seem to be many complaints via a Google Search. All in all, I don't think it's particularly dangerous. And one can always uninstall it before taking one's mac in for servicing.
    – Bruce
    Jun 21, 2013 at 0:47
  • I've been using it for 4 years to run my macbook's fans at a constant 5k, it prevents any sudden temperature build up that'll cause a 6.2k spike.
    – Alexander
    Jun 21, 2013 at 0:48
  • I already have smcFanControl on OSX, but don't see how this can solve the problem... I can only set the minimum fan speed... I don't want that, the minimum should be 2000RPM // Have some new info: today when I started using the computer it was 2000RPM for a while and the temparature was showing 70C. The computer was less hot on the outside that when it was showing 65C. So maybe the first problem is that the temperature reading shown is not right... but there has to be a second problem... This was on Windows, will check the temperature reading on OSX later.
    – davidhq
    Jun 21, 2013 at 10:02
  • Do you have iStat nano by any chance? It's a dashboard widget that gives you more specific temperature readings (i.e.: cpu, hard drive, enclosure, etc). Perhaps it's a hardware problem as cksum suggested: maybe one of the temperature sensors is out of whack.
    – Bruce
    Jun 21, 2013 at 15:05

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