Question about Fan Control apps for iMac

Discussion in 'iMac' started by onthecouchagain, Aug 7, 2011.

  1. onthecouchagain macrumors 604

    onthecouchagain

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    Mar 29, 2011
    #1
    I have a question regarding those fan control iMacs. A little backstory: my 2011 iMac has shut down twice due to overheating (from playing Starcraft II and from watching youTube videos via HTML5), so I'm now wondering about solutions.

    I read a bit about fan control, but I don't understand something: if the iMac can have increased fan speed, why doesn't Apple run them higher than the default settings? If an app can make the fans run faster, why doesn't Apple just build it so the fans run faster by themselves to prevent overheating?

    Or is it that these fan control programs are not good for the iMac? Is there any reason not to set your fan speeds to higher than what Apple has set them to? Do they make the fans' lifespan shorter, damage them, etc?

    If anyone can shed some light on this, appreciate it.
     
  2. 32gb3gwifi macrumors member

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    Jan 29, 2011
    #2
    running them higher probably wont hurt them but apples engineers seemed to be more concerned with fan noise than overheating. i personally havent used them because my imac has been running pretty cool. but i dont see why you couldnt control them manually and run them alittle faster, so long as you dont mind a little noise.
     
  3. maril1111 macrumors 68000

    maril1111

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    Denmark
    #3
    In most circumstances when playing games or doing process-intensive things the Fans have to spin up which gets pretty noisy however it doesn't harm your machine and at a cirtain temperature somewhere over 100degrees celcius your machine shuts down so it seems as if something is wrong with your iMac, if you wanna change your fan speed than the only app that really works is SMCfancontrol try it, http://www.eidac.de/

    and yes you have to put in your user password when first opening it,it is however completely safe to use
     
  4. onthecouchagain thread starter macrumors 604

    onthecouchagain

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    Mar 29, 2011
    #4
    Yeah I'm testing out SMC Fan Control. Very neat app.

    What's a good minimum fan speed to put your iMacs on? Are these safe speeds that I have?

    The first one is what my settings are, and the 2nd pic is Apple's default minimum fan speed.
     

    Attached Files:

  5. DJJAZZYJET macrumors 6502

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    #5
    SMC Fan Control

    A new version was just released and its the BEST fan control app, forget about people saying i dont know why you want to control your fans etc, it makes a huge difference when playing a game, the fans dont spin fast enough as it tries to stay as quiet as possible, but when playing a game i dont notice the fan power until its quiet.

    http://www.eidac.de/?p=207

    Play around with it, you can save fan settings and when you intall it you get an ugly temperature meter, make sure you check the settings and change it into an icon that looks much nicer.
     
  6. onthecouchagain thread starter macrumors 604

    onthecouchagain

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    Mar 29, 2011
    #6
    Also, I think it's ludicrous that Apple actually cares more about minimizing fan noise than preventing the entire system from overheating and crashing. How does that make any sense? Especially when clearly they can ramp up fan speeds.
     
  7. DJJAZZYJET macrumors 6502

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    Jun 4, 2011
    #7
    The fans speeds try to stay low ALL the time, if things are getting toasty (70 degrees), crank em' up for a few minutes, then bring them back down. Im sure the user would understand. My reccomendations for a nice quite but cool computer are to have all the smc fan settings at 1250, you cant hear a thing but they keep it cool when just browsing the web or light stuff, just a default fan speed.
     
  8. Spike88, Aug 7, 2011
    Last edited: Aug 7, 2011

    Spike88 macrumors 6502a

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    #8
    IMO, Apple want to keep their fans at lower RPM in order to keep their Energy Star certification (on their iMac line). If their iMac uses "too much" energy, they cannot promote their boxes as electrical usage "energy efficient". The other reason for slow RPM fans is noise. Faster fans is louder noise. Some (many) folks want their iMac to run silent. Super silent. I like a near silent running computer system as well.

    To me, there's "too much" stuff being packed into a small slim box design. Especially the hotter running i5, hotter running i7, hotter running video cards and hotter running Lion. Add all this together in the old too slim" iMac box design and the extra heat is being trapped. Trapped because the box does NOT have larger size top and bottom vent holes. Vent holes to allow more natural flow over "vertical" air. Think of it this way.... One has a engine compartment for a V6 engine. Its runs cool. If one then installs a much larger V8 engine in the same space (with same fans / rad), that engine is now going to run hotter. Much hotter. To me, if a larger engine is installed, then larger fans & more natural air flow must be installed as well. Thus, much larger bottom and top vent holes (in the iMac box) for the larger size items must be installed as well. Currently, the 2011 iMac boxes uses the same case - as early 2009 / 2010 iMac 21.5" & 27" boxes (with the much cooler parts).

    Drive until it auto shuts-down? Some folks think this way. For me, driving something until its "too late" hot temp light comes on is like waiting for a "too late" signal. Too late because "extreme over heat" damage is already done. Thus, why many auto mechanics call it the "too late" warning lights. If an iMac shuts down from over heating, its "too late" as well.

    Long mumblings short... Apple hasn't realized that more "new technology" parts inside the box = more heat = very bad in the long run. They should have created more (larger size) bottom and top vents - for its new technology hotter insides. Perhaps their next iMac design - after large number of current "over heated" warranty returns ???? Only time will tell...

    .
     
  9. Spike88 macrumors 6502a

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    Jan 25, 2010
    #9
    onthecouchagain,

    My iMacs Fan control (older program) is set at

    [​IMG]

    Note: For my i3 iMac, I've discovered between 1,200 and 1,400 RPM works great. Keeping the DVD helps keeps its GPU cooler.
     
  10. Spike88 macrumors 6502a

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    Jan 25, 2010
    #10
    onthecouchagain,

    For my iMac 21.5" 3.2, the default FAN RPMs for SMC Fan Control 2.2.3 (the newest version) is shown below.

    Interesting that this software upgrade program sets "minimum" RPM = 1,500-1,600 range. And, Apple has their minimum defaults set to 800-850ish. Very interesting...

    If wondering, I'll leave it at 1,500 - 1,600 RPM for now. Will analyze if its temps drop lower (current at 35C @ 1,600 RPM). Will be using iStats Nano to gather detailed temps on its different internal sensors...

    [​IMG]
     
  11. onthecouchagain thread starter macrumors 604

    onthecouchagain

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    Mar 29, 2011
    #11
    Thanks for sharing your values Spike. Any particular reason why your HDD fan speed is at 1500 RPM? That's a bit higher than what i have (around mid 1300's). Should it be raised higher?

    And how important is the Optical Disc fan speed when you're not using the DVD slot?
     
  12. Spike88 macrumors 6502a

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    Jan 25, 2010
    #12
    Based on the above picture, 1,500 RPM is as low (to the left) as the slider will go. Guess version 2.2.3 of Fan control doesn't like my i3 iMac. Perhaps I should have kept using the older version of Fan Control S/W.
     
  13. 32gb3gwifi macrumors member

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    Jan 29, 2011
    #13
    your optical disc fan is for the the disc drive AND your gpu heatsink, so its VERY important.
     
  14. tasty-the-dog macrumors newbie

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    Jul 31, 2011
    #14
    My problem isn't in OSX, it's when I'm gaming in Windows. the iMac gets significantly hotter, as if the fans are disabled or something. The only solution I've found online is people starting a fan control app in OSX and then restarting into Windows (and even then some people say it works and some don't). Is there any program that can be downloaded that lets you control the fans IN Windows? Ideally I'd like to manually increase the fan speeds there and leave everything exactly as it is in OSX. Loving Bootcamp and being able to game in Windows (haven't played PC games since the Wing Commander days) but don't want to screw my new iMac up in the process as it's also my work computer. Any ideas? Thanks.
     
  15. 88 King macrumors 6502

    88 King

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    Jun 18, 2011
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    London, UK
    #15

    I use Mac/SMC Fan Control for Windows. This allows you to adjust min speed of the 3 fans within Windows.

    http://sourceforge.net/projects/macfan/

    P.S. My 2011 imac is able to retain fan speed changes I made using iMacs Fan control rebooting from Lion to Windows.
     
  16. onthecouchagain thread starter macrumors 604

    onthecouchagain

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    Mar 29, 2011
    #16
    Ah, no wonder! My GPU heats are very high when running Starcraft II (70+ degrees Celsius), while everything else remained reasonably lower. I will readjust the ODD fan when I get home. Thanks for sharing that info.
     
  17. Spike88 macrumors 6502a

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    Jan 25, 2010
    #17
    Today, I had some spare time to play with it.. re: Why I couldn't change the default 1,500 RPM values.

    Found the problem / fixes. They were:
    - Copied application to my "Applications" folder.
    - Within the application, had to make a new profile (called iMac 21,5) instead of using their "default" profile. Their default profile was minimum @ 1,500 RPMs.
    - Had to remove the older SMCFan Control item from Library - Startup folder.
    - I then had to create a System Preference - Account - SMC Control Program (pointing to SMC Control Program stored within Application folder).
    - Now, I set all all fans to minimum 1,325 RPMs and it runs great. Much cooler then Apple's default 900 + 1,000 RPMs. And, quieter than previous 1,500 RPM. To me, 1,325 RPM is perfect middle round. And, I get a nice TEMP & FAN RPM in the top status bar.

    Now, I leave it... Will run that for a while...

    .
     
  18. Spike88 macrumors 6502a

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    Jan 25, 2010
    #18
    After few hours of "typical" usage, the new SMC Fan control 2.2.3 is working great. I'm monitoring its HDD - on the top menu bar. Currently showing 36C @ 1390 RPMs. Based on iStats Nano, its other temps are between 35 - 48C (with Ambient at 22C). Nothing in the 50C range. Nice and cool - as expected.
     
  19. tasty-the-dog macrumors newbie

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    Jul 31, 2011
    #19

    awesome, thanks!
     
  20. onthecouchagain thread starter macrumors 604

    onthecouchagain

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    Mar 29, 2011
    #20
    My power supply temp seems to hover around 62-70 degrees. Is this normal? Using SMC Fan Control, which fan would help with the power supply more? ODD, HDD, or CPU?

    Also, I honestly don't ever hear my iMac's fans, not even at 1500 RPMs.
     
  21. bumzo1 macrumors 6502a

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    Jan 31, 2009
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    Dallas, TX
    #21
    I use istat menus to help monitor temps and control fan speeds as well as some other information. It works really well and is very easy to use. You do have to pay for it however, about $15 I believe but its worth it
     
  22. onthecouchagain thread starter macrumors 604

    onthecouchagain

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    Mar 29, 2011
    #22
    New question: do the fans continue spinning at the levels you set when it goes to sleep? Or do they stop spinning altogether?

    My GPU and Power Supply seem to be the hottest things. Always hovering around high 50's Cel when not playing any games. It can get as high as 60-70 when playing SC2. And this is with higher fan settings.
     
  23. 88 King macrumors 6502

    88 King

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    Jun 18, 2011
    Location:
    London, UK
    #23
    There is no power going to the fans when the imac is in sleep mode, so the fans are off.

    There is nothing we can do about the GPU and PSU temperature other than speed up the fans and put the imac in a cooler room. Price we pay for all-in-on machine.

    You can use shift+ctrl+eject to turn the screen off and let the imac cool off before it goes into sleep mode.
     
  24. jean01 macrumors newbie

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    Jun 27, 2011
    #24
    hi everyone !

    i'm trying to install smcfancontrol 2.3 on a base model 21.5 inch 2011 with sl...and got a alert message "smcFanControl has not been tested on this machine."
    what does that means? should i ignore it ?

    Thanks for your advices
     
  25. Spike88, Aug 9, 2011
    Last edited: Aug 9, 2011

    Spike88 macrumors 6502a

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    Jan 25, 2010
    #25
    Yes. I got the same warning msg as well (on my iMac). Simply ignore it.

    After installing, restart computer to confirm it auto-loads and its temps/fan RPM numbers appears on the top menu bar. For my iMac, it had "minimum" fan speed of 1,500 / 1,600 RPMs. To reduce their default RPMs, I had to create a different profile. For example, instead of using their "default" profile, manually call it "my imac". Then, one can turn the 3 x fans down to 1,200 RPM (as minimum). For my iMac, I found customized 1,300 to 1,400 rpms "minimum" range is best. If wondering, Apple default fan RPM speeds on my iMac is 900 - 1,000. To me, this is too low. Inscease to 1,300/1,400 RPMs and my iMac runs much cooler. Removing the memory sim cover from the bottom of the iMac screen (that cannot be seen anyway) helps keep the iMac insides cooler as well. re: It lets more cooler air into the bottom of the iMac box.

    If SMC 2.2.2 was previously installed, you may have to manually "drill down" your iMac's HD - Library - Startup folder and remove (trash) the old SMC Program icon from this folder. If wondering, I had to perform this manual removal task on my iMac.

    Also... SMCFan Contol 2.2.3 isn't a complete solution. re: Wished it showed all 5 heat sensors instead of only the 3 main sensors. Thus, I also use iStats Nano to validate internal temps and internal fan RPMs - of its other sensors as well. Their 3:3 main readings don't align 100%, but are close enough.

    Hope this helps...
     

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