iMac HDD Fan running a lot

Discussion in 'iMac' started by gavroche, Jan 14, 2016.

  1. gavroche macrumors 6502a

    gavroche

    Joined:
    Oct 25, 2007
    Location:
    Left Coast
    #1
    My HDD fan is running at 5495 rpm, and seems to pop up to that a lot... yet the temperature sensor says its only 34C.... so seems unnecessary. And i'm not currently doing anything at all... just web browser. Should i be concerned about this? (iMac i5)
     
  2. gavroche, Jan 14, 2016
    Last edited: Jan 14, 2016

    gavroche thread starter macrumors 6502a

    gavroche

    Joined:
    Oct 25, 2007
    Location:
    Left Coast
    #2
    Hmm.. so i've done a bunch of reading at various locations on the subject, and come up with the following:
    1) Seems that 2009/2010 model iMacs have a common problem experienced by people that have upgraded their HDD's. The culprit perhaps seems to be that the cable used to connect the sensor is not fully/properly seated into the new drive. As my iMac has a 1TB drive, and this is the default configurations size for this model, i can't assume that the drive has been replaced causing this problem.
    2) smcfancontrol, the app recommended in many locations that are discussing fan control, isn't really much help for the type of problem i'm experiencing. This app only controls the MINIMUM fan speed. Especially, it lets you raise (but not lower) the minimum fan speed higher than the apple default. Since my fan is running faster than it should already, would not help me.
    3) There is an app called HDDFanControl. ( http://www.hddfancontrol.com ). It claims to use different sensors than what's used through that cable that isn't always seated properly. And it claims to help LOWER fan speed. Seems good. But the app is $35.. which to me seems a lot to not know for sure if it works. They have a free trial, but it's only a 1 hour trial. Yikes. I'll probably give it a go. If that don't work, i guess my new step is to try to open up the iMac and check out that HDD, and it's cable connection...

    Update: I installed the HDD Fan Control app.. and the fan in the iMac immediately dropped from 3700 down to 1090.... and for the full hour trial, it stayed right in the range of 1000-1100, where it is supposed to be. I carefully watched the temperature of the cpu, hdd, etc... while i put it through a lot of usage during that hour. all looked good. But right at the end of the hour, it popped up a window letting me know my trial had ended... and the fan shot right back up to 5000rpm. Ugh. Guess i have no choice but to buy the app...
     
  3. gavroche thread starter macrumors 6502a

    gavroche

    Joined:
    Oct 25, 2007
    Location:
    Left Coast
  4. gavroche thread starter macrumors 6502a

    gavroche

    Joined:
    Oct 25, 2007
    Location:
    Left Coast
    #5
    Update:

    Was using SSD Fan Control to return fan to normal quite usage. (this pertains to the issue that many people faced using 2009/2010 model computers who upgraded the internal hard drives... and there was some issue with one of the two methods the OS can use to monitor temperature and speed. a third party app such as this one uses the alternative method). Note that although i'm not using a SSD, this app worked the same regardless, and it is free.
    I thought i'd mention to anyone that just upgraded to MacOS Sierra that after the upgrade this app may stop working. The website for the app looks to have not been updated for a long time. But i noticed that it had a comment that after upgrading to 10.11, if it stopped working, you should uninstall and reinstall. So i thought that the same may hold true for Sierra. So i tried this, and sure enough its working again.
     

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