I recently upgraded my HDD to a SSD. Before upgrading I never checked fan speed. Now, after my upgrade the fan spins at 1400 rpm on idle.

Is this normal? I thought it would be quiet like on a MacBook Pro, with the fan turning on after it reaches a certain temperature. However, it seems to me the fan is now on sooner and because of this my iMac is noisier than before.

Can someone who has original hdd check fan speed and temperature and post it here?

  • 1
    Your question doesn't clarify why you decided to check the fan speed now (after the upgrade) when you never used to. Was there something that prompted you to do this? Did something concern you, or you just decided to check?
    – Monomeeth
    Feb 12, 2017 at 23:16
  • I thought that after upgrade my mac should be quite, but i heard noise, so i decide to check fan speed. Before upgrade was normal that is not quite becouse HDDs are noisy
    – Sakac
    Feb 13, 2017 at 5:08
  • On the Macbook Pro the fans are always on (approximately at 2000 rpm on idle). Does the iMac have a dedicated fan for the SSD? Are you sure it was off before?
    – n1000
    Feb 13, 2017 at 10:51
  • on my macbook pro fan is on over 55 degrees C. imac has only one CPU fan. I am not sure it was off before.
    – Sakac
    Feb 13, 2017 at 18:04

1 Answer 1


A fan speed of 1400RPM really is nothing to worry about. And your model iMac does not require an external thermal sensor for an ssd upgrade, so that shouldn't be an issue for you.

My first step would be to try resetting your System Management Controller. To do this:

  1. Shut down your computer
  2. Unplug it from power
  3. Wait 15 seconds
  4. Plug the power cord back in
  5. Wait for an additional 5 seconds
  6. Press the power button to turn it back on

Software option

You can also try installing SSD Fan Control to see if that resolves your issue. However, I would only do that if the SMC reset does not resolve your issue.

  • i already did reset SMC but nothing changed. I am not sure if fan must and can be on all the time, or not.
    – Sakac
    Feb 13, 2017 at 18:09
  • The problem we have is that it isn't at all clear that you actually have a problem. Computer temperatures and fan speeds vary greatly. You can check here to compare temperatures (the list can be sorted), but otherwise if you're experiencing any other issues or just feel concerned, try installing SSD Fan Control (as per my answer) to see if this has any effect on your situation. By the way, for future reference, when posting a question it's good practice to detail what you've already tried (e.g. resetting the SMC).
    – Monomeeth
    Feb 13, 2017 at 21:12

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