Retina iMac noise

Discussion in 'iMac' started by omenatarhuri, Oct 23, 2014.

  1. omenatarhuri macrumors 6502a

    Joined:
    Feb 9, 2010
    #1
    Hey,

    Some reviews seem to mention that the retina iMac is usually quiet, but the fans can 'definitely be heard' when they kick in.

    Please share some experiences on the topic if you have received you retina iMac and have done some heavy computing like a long export, rendering or gaming on it. Something that really puts the system to its limits continuously for hours (or at least 30 mins).

    I'd be especially interested to hear from those with the i7 processors and 295x GPU. Also any experiences regarding 1TB fusion drive noise is welcome.
     
  2. thagomizer macrumors 6502

    Joined:
    May 26, 2005
    Location:
    USA
    #2
    I've had my Retina iMac 27" 4GHz M295X with 1TB fusion drive running for about 8 hours now, and the fan is on constantly. It's a definite whir or hiss, sounds like white noise, and smcfancontrol reports it's 2160rpm. The CPU is 102 degrees F.

    Is this normal? If I quit smcfancontrol, the fan is still running at the same speed. It's about as loud as a 13" MacBook Pro's fan at full blast, that's the only thing I can subjectively compare it to.

    I checked Activity Monitor, and the computer isn't doing anything.

    I did put in an extra 16GB of Crucial RAM, for a total of 24GB. The RAM shows up, so I'm sure I installed it properly.

    ----------

    I rebooted it, and the fan noise was on constantly throughout.

    So I shut down, started up again, and the fan noise started only when it reached the desktop. Still just as loud. Now 111 degrees, 2162 rpm.
     
  3. 8CoreWhore macrumors 68020

    8CoreWhore

    Joined:
    Jan 17, 2008
    Location:
    Big D
    #3
    What I don't understand is why your fans would be so loud while running at their low, idle, speed. My rMBP is silent at that speed, and at only 85F with general use.

    Try another app to see fan speed. I wonder if they are actually going faster than SMC suggests. Try iStat Menu free trial and see.
    http://bjango.com/mac/istatmenus/
     
  4. thagomizer macrumors 6502

    Joined:
    May 26, 2005
    Location:
    USA
    #4
    Wow, that's a really nice application. Ok, iStatMenu shows exactly the same fan speed as the smcfancontrol menu. But it's pretty loud at 2160 RPM right now.

    I took out the Crucial RAM, by the way. Made no difference to the fan.

    ----------

    It's getting louder! I can hear it across the room. In back i put my hand and I can feel air coming out, slightly warm. Not hot at all.
     
  5. thagomizer macrumors 6502

    Joined:
    May 26, 2005
    Location:
    USA
    #5
    Retina iMac owners please respond

    Retina iMac owners, what is your fan speed when the computer is doing nothing? Would you please measure with one of the aforementioned programs and post here. 2100rpm may be normal for a laptop but it seems high for a large desktop fan. I've seen pictures in the iFixit tear down, it's huge.
     
  6. redheeler macrumors 603

    redheeler

    Joined:
    Oct 17, 2014
    #6
    Yeah, that's definitely not normal. Mine hovers around 1200 rpm on idol (in smcFanControl). It's barley discernible if I'm not doing something CPU intensive, although when I am I definitely hear it kick in. I also have 16 GB Crucial RAM installed, by the way, although I doubt that has anything to do with it.
     
  7. thagomizer macrumors 6502

    Joined:
    May 26, 2005
    Location:
    USA
    #7
    Thank you. Ok, I'll call AppleCare tomorrow. Thanks again.
     
  8. WilliamG macrumors G3

    Joined:
    Mar 29, 2008
    Location:
    Seattle
    #8
    1200rpm sounds right. My 2012 27" iMac idles at between 1192-1208 depending on what iStat Menus is reporting. So 1200rpm is probably the aimed speed, which varies +- % points of rotations. 2160 is what it would be under load. I'd suggest resetting SMC/PRAM and see if that helps, before calling Apple.
     
  9. thagomizer macrumors 6502

    Joined:
    May 26, 2005
    Location:
    USA
    #9
    I tried SMC reset several times to no avail. So I did a complete wipe and reinstall of Yosemite using a thumb drive installer. Now, computer is completely silent even with the extra memory back in. So the problem was some software I had (I brought everything over from an external backup using migration assistant).

    So now I just need to figure out which of the software I've accumulated over the past 13 years of OS X is causing my fan to run up.
     
  10. bp1000 macrumors 65816

    Joined:
    Jul 7, 2011
    #10
    I had trouble with my iMac last winter. I got through about 4 before settling on a unit which still had noise.

    2 I tried had a definite fan whir like noisy bearings the other 2 had a slight crackle when the screen brightness was below 4 bars and there is a dark background on the screen.

    Delving into the reason for this noise it seems iMacs have always suffered from screen crackle or fan hum. Seems the retina iMac is not exempt.

    Be aware that not all ears can detect these noises and low abient noise also amplifies the issue.
     
  11. trims macrumors regular

    Joined:
    May 11, 2011
    Location:
    Nottingham, UK
    #11
    Is this not the standard new computer behaviour - indexing files / backing up etc?? Leave it for a day or two and maybe things will settle down?
     
  12. thagomizer macrumors 6502

    Joined:
    May 26, 2005
    Location:
    USA
    #12
    I did a second restore from migration assistant, rebuilt permissions, and deleted smcFanControl. Not sure which of those did the trick, but the noise has not come back. Maybe something went wrong in the first migration.

    iStatMenu shows fan speed as 1196. Much better. Thanks everyone for your suggestions.
     
  13. macnerd77 macrumors regular

    macnerd77

    Joined:
    Jan 9, 2007
    Location:
    Northern California / Bay Area
    #13
  14. hyune83 macrumors member

    Joined:
    Sep 19, 2008
    #14
    Any difference in fan noise between the retina and the older iMacs?
     
  15. xgman macrumors 601

    xgman

    Joined:
    Aug 6, 2007
    #15
  16. robgendreau macrumors 68040

    Joined:
    Jul 13, 2008
    #16
  17. xgman macrumors 601

    xgman

    Joined:
    Aug 6, 2007
    #17
    Same exact config here except I have a 1TB SSD, but same problem as I already stated. I suspect it is the 4ghz processor that is heating things up.

    ----------

    Could something have been going on like long spotlight re-indexing or TM etc? If so, it might spin up again at some point.
     

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