imac 21.5 is wayy too hot?

Discussion in 'iMac' started by dfusion-, Jul 21, 2010.

  1. dfusion- macrumors member

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    Jan 15, 2010
    #1
    [​IMG]

    my imac is feeling very hot! and getting a bit scared of it..should i be afraid?

    if not..when should i be afraid?:D
     
  2. Hellhammer Moderator

    Hellhammer

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    #2
    Those temps are completely normal. When your HD reaches 60c, you should think about boosting the fans but otherwise those are normal.
     
  3. wordoflife macrumors 604

    wordoflife

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    Jul 6, 2009
    #3
    You should be scared when your processor gets over 100C.

    My Macbook Pros processor gets to 70c all the time. Nothing to worry about.
     
  4. dfusion- thread starter macrumors member

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    Jan 15, 2010
    #4


    thanx men:) another question..how do you boost up the fans?:O i dont see any controls in symstem preference..
     
  5. Hellhammer Moderator

    Hellhammer

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    #5
    SmcFanControl
     
  6. dfusion- thread starter macrumors member

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    #6
    thank u for the great help :)!
     
  7. AlexisV macrumors 68000

    AlexisV

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    #7
    You don't need to mess about with fans.

    The top left of the machine will get extremely hot under load because it is funnelling heat away from the inside.

    I suspect your car radiator gets quite toasty as well.
     
  8. Hellhammer Moderator

    Hellhammer

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    #8
    Keeping the components cooler will decrease the risk of failure. Heat is never good for them, the cooler the better. It's not needed but such small thing to do and it might keep your machine running longer
     
  9. AlexisV macrumors 68000

    AlexisV

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    #9
    ..assuming Apple have designed their machines not to last as long as possible on purpose by including sub standard heating.

    Really? :rolleyes:
     
  10. Hellhammer Moderator

    Hellhammer

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    #10
    I didn't say it will blow up. Heat still isn't a good thing, believe it or not. There are plenty of logic board failures in iMacs but normal desktops rarely have a fried motherboard. Heat is at least one of the reasons for that as iMacs run ~15c hotter in my experience.

    Speeding up the fans may or may not extend its life but there is no harm done. It does feel safer when your temps are lower
     
  11. Stealthipad macrumors 68040

    Stealthipad

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    Apr 30, 2010
    #11
    I know Apple does not want to "degrade" the looks of their iMac package but I always thought that a few holes in the back of the iMac would go a long way to help cooling.

    I do think they are SO obsessed with how the iMac looks that they will sacrifice the dependability of the hardware over the long run to preserve the "sleek looks"!

    A few "holes" would also open up opportunities for new processors!
     
  12. AlexisV macrumors 68000

    AlexisV

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    #12
    You're going to need some stats to back that up :rolleyes:
     
  13. aki macrumors 6502a

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    #13
    I hate to be one of "those people" but - there are a million threads on this, seriously. :eek:

    How much heat is too much heat all depends - how long you want your mac to last, what you use your mac for, and how good your backup plan is.

    For myself, I don't like the HD getting near 55, and I try to keep it close to 50. I am a moderately heavy user (video editing and gaming), and I use Windows a lot (for gaming).

    To control fans I use smcfancontrol. There are more sophisticated options coming apparently (including ones that run under Windows), but for now smcfancontrol does the job.
     
  14. Zoobiee macrumors newbie

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  15. miniroll32 macrumors 6502a

    miniroll32

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    #15
    When I encode from Handbrake, my MacBooks CPU goes to 102c. Go figure!
     
  16. IndustrialSpace macrumors 6502a

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    #16
    This topic comes up often.

    Are Apple iMacs built without sincere consideration for the cooling aspects?

    Does one have to install and configure their fan controls. Will the iMac fail prematurely due to cooling issues?

    Why hasn't Apple done soemthing to address this. Why isnt there a software patch to automatically adjust fan speeds.

    Is this all really necessary or are iMacs so fragile that they will fry quickly.

    I tend to trust Hellhammer, so it does seem like one needs to have extra software and monitor their temps as the factory software does not do the proper job. If this is indeed the case, then I think Apple has a scam going to decrease the life of these computers so as to either sell more AppleCare or parts.

    One more reason to be cautious about an iMac purchase, I guess. Personally, I dont want to tweak the factory fan settings. Doesn't sound like a good idea, but perhaps necessary if you dont want these "ovens" to cook your circuits.

    Lets hope the next iMac revison has better fans or cooling software installed. Having to use aftermarket software to monitor and control what SHOULD be expected and standard in a $2-3K computer, seems unacceptable.
     
  17. Hellhammer Moderator

    Hellhammer

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    #17
    There isn't need to adjust the fan speeds. It's more like "well, it doesn't hurt and I'm paranoid with temps" :D It will work fine with default fan speeds, I have raised mine like ~200rpm per fan. That keeps my HD at ~50c but there is no extra noise. My CPU still gets over 80c when encoding with HandBrake, I would have to make it sound like an airplane to cool it more. Besides, 80c is normal for CPU when under full load.

    Most people don't do anything and their iMacs are just fine. For me, it's a left over from PCs, I always liked to hassle with the fan speeds and still like.
     
  18. CAScading macrumors newbie

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  19. aki macrumors 6502a

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    #19
    Everyone duck! Aki's Ginormous Heat Post Incoming! :p

    ----

    There are lots of very informative threads on this topic. Here is my considered view for what it's worth.

    Firstly, iMacs do run on the hot side. They are pretty cramped (yes even the 27") and designed to be svelte. That has a cost.

    Second, they get hot to the touch. This is most certainly by design. Touching your iMac tells you nothing except that the heat dissipation is working well. If you want to know what's going on inside, which is the point, use iStat or similar.

    Third, for normal use, the iMac does not require user intervention. This begs the question "What is normal use"? Here's my take. If you upgrade your hardware regularly, don't worry about temps. If you want or may want your iMac to last into the 3 to 5 year range, you should give it a thought. If you use your iMac mostly for email and websurfing and writing papers, forget about temps. If you do marathon gaming sessions, if you often game in bootcamp Windows, or if you do video processing or other "heavy lifting", you should give temps some thought.

    Fourth, most people who worry about temperatures worry about them needlessly; see point three above.

    Fifth, if you do use your iMac for heavy work or often use Windows and do want your machine to last a bit longer or at least know what's going on, the current prefered solution (imo) is iStat or Temperature Monitor or similar, which will give you temps in the menubar or in the Dashboard (OSX side only), and smcfancontrol, which will let you manually set minimum fan speeds (the setting can only be done from OSX, although you can have the fan speed settings carry over to a bootcamp Windows session provided you do a restart and don't switch off the iMac).

    Sixth, if you are setting fan speeds and looking at temps, what should you be looking for? The GPU and CPU are precious and expensive to replace obviously but they are also rated for quite high temperatures. The iMac is designed to shut itself down before you get to that point. What is rather more fragile is your internal HD. High temperatures don't kill HDs immediately, but they do reduce lifespan/increase failure rates. Of course you should be timemachining or similar anyway; but replacing a HD is tedious and stressful and can be very inconvenient. Again, having given due consideration to the points above, I think it's good to set speeds to keep your HD temps in the low 50s C. Under 50C is fine, over 55C is bad, in between is, well, reasonable given what the iMac is. (I should note when I talk about temperatures here I'm talking about high temperatures suistained over a period of time. Spikes in temperature, when you are transcoding a youtube clip or something, that's not worth being concerned about. I'm thinking here about all-night Crysis sessions or whatever.)

    Seventh, and final point. Environmental conditions play a role (more than I originally thought). Depending on where you live, ambient temperatures will have an effect - I'm in Japan and temps are clearly higher in summer than winter inside the iMac. Also, if you live in a dusty environment, it's not a waste of time to dust around your machine and desk regularly - your fans will suck up that dust over time.

    Eighth and actually final point. External fan solutions sound better than they may actually be. I'm not an engineer of any description, but I have read authoritative-sounding accounts of how the fans in the iMac are carefully and cunningly placed so as to maximize efficiency, by directing airflows from certain areas to other certain areas over so and so components. Which is to say, it's all a pretty neatly designed system. There used to be mods around where people would carve holes in the backs of their G5s (this is in the plastic era), and electrical-tape fans on there or what have you. Bad idea (generally speaking) - it just messes with the airflows that some team of very clever Apple engineers burnt countless nights laboring over. Or something. I'm being verbose, the point is, placing little desk fans at the base of your machine or pointing your fan at the air vent in the back might look like its helping - hey, it's cool air, right? - but it may or may not actually be that simple.

    Ok I'm done. Good luck! :)

    PS Ok I lied about being done - if you do elect to use smcfancontrol, it's generally better to trying uping all three fans a small amount than one fan a lot. Again, they are designed to work in concert.

    Update: iStat Menus versions 3 and above (no longer, alas, a free product) allow you to manage fans similarly to smcfancontrol, along with monitoring a billion other things. Haven’t tested if its settings carry over to bootcamp sessions like smcfancontrol does.

    Updated Update: iStat Menus v3.x.x fan settings do indeed persist over reboots ie you can use it to set your fans for your upcoming 48-hour Starcraft 2 bender. Wheeeee. (Well, presuming you wanted to play SC2 under bootcamp Windows that is.)
     

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