New iMacs Heat Warning and Cure!

Discussion in 'iMac' started by AlanTheBrit, Aug 19, 2007.

  1. AlanTheBrit macrumors member

    AlanTheBrit

    Joined:
    Apr 13, 2007
    Location:
    Runcorn, Merseyside UK
    #1
    ONE VERY IMPORTANT POINT: The default cooling-fans "kick-in" temperature is set (by Apple) WAY TOO HIGH! (at least in my 24" Core 2 Duo 2.8GHz Extreme(X7900)): I implore you to:

    Download 1) Temperature Monitor 4.2 and 2) smcfancontrol_2_1_2: I HALVED the excessive heat in my 24" using these excellent tools! My PSU was running at 84 degrees Centigrade before; and is now at 45 degrees Centigrade (with the same usage conditions).

    Run Temperature Monitor 1st - and be very scared!

    Now run smcfancontrol; set its sliders to mid-point and relax...
     
  2. Eidorian macrumors Penryn

    Eidorian

    Joined:
    Mar 23, 2005
    Location:
    Indianapolis
    #2
    I think the 190° F my Mac mini was running was much worse. -_-

    I try to keep it under 160° F at full load now using SMCFanControl.
     
  3. macenforcer macrumors 65816

    macenforcer

    Joined:
    Jun 9, 2004
    Location:
    Colorado
    #3

    The core duo cpu is designed to go to 194F (90c) then power down to stay at that temp or below. Heat is not an issue. If it ever got too hot it would power down completely before melting. Todays cpus will never melt down.

    I used to freak about temps too but now I just realize its the design speck and is perfectly normal.
     
  4. AlanTheBrit thread starter macrumors member

    AlanTheBrit

    Joined:
    Apr 13, 2007
    Location:
    Runcorn, Merseyside UK
    #4
    I think Apple (from admirably stylistic motives; want the new iMac to be even "cooler" than the previous iteration; even if it means running it at (medium-long term ruinous temperatures). I simply can't afford to replace this beautiful beast in 2 to 3 years time!

    It IS VERY beautiful - no thicker from front to back than most display-ONLY screens...

    I'm still groaning with desire at the mere sight of my glorious antidote to brutal human stupidity.

    Well...
     
  5. rainydays macrumors 6502a

    Joined:
    Nov 6, 2006
    #5
    Hmm, I wonder if this could be an issue with the 2.8GHz or if it's an issue with certain machines only. Because I have normal readings on this 2.4Ghz, even after hours of heavy load both on the CPU and the GPU.

    The power supply is normally between 50-60 celcius, and I don't think thats something to worry about. The CPU cores vary between 35 and 60 degrees while the gpu is usually about 50-60 degrees.

    Do you have a badly ventilated hot room or something? I would return it if I got that high temperatures under normal conditions.
     
  6. rest44 macrumors member

    rest44

    Joined:
    Sep 24, 2006
    #6
    If that was really a problem, why do they put vents kick in at a temperature so high?
     
  7. AlanTheBrit thread starter macrumors member

    AlanTheBrit

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    Apr 13, 2007
    Location:
    Runcorn, Merseyside UK
    #7
    Point taken; but, nevertheless, cooler IS cooler!

    Something that's close to 212 degrees Farenheit (BOILING POINT!) is plain frightening... I'll keep using Fan Control... :))
     
  8. Eidorian macrumors Penryn

    Eidorian

    Joined:
    Mar 23, 2005
    Location:
    Indianapolis
    #8
    To the best of my knowledge it's 100° C (212° F) for the Core Duo.

    I understand that it wasn't in any sort of danger but I didn't want it running that hot.
     
  9. AlanTheBrit thread starter macrumors member

    AlanTheBrit

    Joined:
    Apr 13, 2007
    Location:
    Runcorn, Merseyside UK
    #9
    "Temperature Monitor 4.2" monitors ALL temperature zones! I.e., HD; Optical Drive; PSU etc. In the UK (currently), and in my room, the temperature is 24 degrees Fahrenheit...

    Not just the CPU. ALL zones were at very high temperatures...
     
  10. AlanTheBrit thread starter macrumors member

    AlanTheBrit

    Joined:
    Apr 13, 2007
    Location:
    Runcorn, Merseyside UK
    #10
    HELL NO!!, its 24 Centigrade... these pesky heat issues...
     
  11. macenforcer macrumors 65816

    macenforcer

    Joined:
    Jun 9, 2004
    Location:
    Colorado
    #11
    Actually no. The processor is made to shut down at 125c. I think that the thermal settings are governed by apple though. So at 90c it slows down and fans turn on high speed. Mine never went past 89c so that is my theory. The cpu for sure will shut down at 125c though. Check it.


    Intel design spec for core duo
     
  12. AlanTheBrit thread starter macrumors member

    AlanTheBrit

    Joined:
    Apr 13, 2007
    Location:
    Runcorn, Merseyside UK
    #12
    This same excessive heat in 2.8GHz iMacs has been reported elsewhere...

    I thank those people and programmers for my present peace of mind (on this issue).

    Best

    AlanTheBrit.
     
  13. Eidorian macrumors Penryn

    Eidorian

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    Mar 23, 2005
    Location:
    Indianapolis
    #13
    I was looking for that documentation.

    Thanks
     
  14. AlanTheBrit thread starter macrumors member

    AlanTheBrit

    Joined:
    Apr 13, 2007
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    Runcorn, Merseyside UK
    #14
    125 Centigrade is classed as a CATASTROPHIC temperature (in Intel's PDF)...
     
  15. Gzilirion, Aug 19, 2007
    Last edited: Jun 13, 2012
  16. AlanTheBrit thread starter macrumors member

    AlanTheBrit

    Joined:
    Apr 13, 2007
    Location:
    Runcorn, Merseyside UK
    #16
    Lest we forget...

    The present iMac is a superb tribute to the efforts of thousands of mega-intelligent and dedicated people. It's something that will remain immortal as a peak human achievement of the early 21st century.

    - Unlike the Iraq disaster... "Living With War" is Neil Young's (humble UK male's personal opinion - somewhat off-topic) masterpiece on that grim subject.

    If only all wars could be fought via virtual reality...
     
  17. Alloye macrumors 6502a

    Joined:
    Apr 11, 2007
    Location:
    Rocklin, CA
    #17
    iStat Pro Readings

    24" Aluminum iMac (2.4GHz) after seven hours of mixed use (Mail/Safari/iTunes/Keynote/Numbers/Xcode):

    CPU A: 39-41C
    GPU: 55-57C
    GPU Diode: 55-57C
    GPU Heatsink: 52-54C
    Ambient: 23-24C
    Memory Controller: 46-48C
    HD Bay 1: 51-52C
    Optical Drive: 41-45C
    WDC WD3200AAJS: 51-52C
     
  18. JimmyDreams macrumors 6502

    Joined:
    Jul 24, 2007
    #18
    Aside from the Iraq sidebar (*cough* inappropriate political handgrenade *cough*)....

    Are the new iMacs warm/hot? Maybe. Warm to me might be hot to you. But specs don't lie and unless the fine folks at Apple are smoking crack, I HAVE to assume their technicians and engineers took the design specs and made them match the tech specs. Anything less would mean a meltdown (thank yew) for their PR department.

    That said....is running iStat and changing the fan kick-in points a bad thing? Nope, I'd say not at all. Unnecessary, but not bad.

    Now...on to more important things....like why isn't my new iMac listed as 'prepared for shipping'? Someone get those workers BACK to work making my new (and first) iMac!!! ;)

    JimmyD (HALO MacAddict due to my iPhone)
    :apple::apple::apple::apple:
     
  19. AlanTheBrit thread starter macrumors member

    AlanTheBrit

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    Apr 13, 2007
    Location:
    Runcorn, Merseyside UK
    #19
    Note: I've looked into this further and my iMac 2.8GHz temperatures were grossly high compared to the norm. Note also, Apple from time to time issue "fan-fixes" for other Macs.
     
  20. Sean Dempsey macrumors 68000

    Sean Dempsey

    Joined:
    Aug 7, 2006
    #20
    I've got the SMC fan controller running just slightly, here's what I am getting. It brought down the HDD temp a bit it seems, but I am worried about fan noise and wearing out the fans prematurely. I am not totally sure the computer needs the extra cooling yet.
     

    Attached Files:

  21. mrmjd macrumors regular

    Joined:
    Jul 7, 2007
    #21
    I was in the Apple stor late on Friday and touched the iMacs and they were pretty cool considering they would have been on and used all day. Wonder what their setting is at?
     
  22. Eidorian macrumors Penryn

    Eidorian

    Joined:
    Mar 23, 2005
    Location:
    Indianapolis
    #22
    I fail to see how you'd be greatly increasing the mean time before failure before you replace the computer.

    Fan noise is a byproduct of running the fans at a higher speed. You can either deal with it or clock the fans back down and deal with the heat.
     
  23. Sean Dempsey macrumors 68000

    Sean Dempsey

    Joined:
    Aug 7, 2006
    #23
    Doubling the RPM would double the wear and tear, I presume. If a fan only has a certain amount of hypothetical revolutions, I would hate to have a bearing seize inside an iMac and not know about it.
     
  24. AlexisV macrumors 68000

    AlexisV

    Joined:
    Mar 12, 2007
    Location:
    Manchester, UK
    #24
    Don't worry. Apple will have tested them for days on end at full load to make sure they didn't melt!
     
  25. flopticalcube macrumors G4

    flopticalcube

    Joined:
    Sep 7, 2006
    Location:
    In the velcro closure of America's Hat
    #25
    The MTBF of a fan is far higher than that of almost any other component in the iMac.
     

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