The cooling system in the 27" 2012 iMac is nothing short of brilliant.

Discussion in 'iMac' started by WilliamG, Dec 30, 2012.

  1. WilliamG macrumors 604

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    #1
    I really, truly believe this deserves its own thread. Yes, the 2012 iMac design sacrifices some things to achieve that thin edge, but its cooling is not one of them.

    I had a 2009 i7 27" iMac, and that thing ran warm. The top of it would be a toaster oven whether busy or idling. It was baking hot.

    By comparison I've been using my loaded 2012 iMac (i7/32GB RAM/Geforce 680MX) all evening and the thing is actually cold everywhere. Right, it's not lukewarm - it's COLD. Whether you love or hate the new design, there's no question Apple has the temperature issue addressed with this 2012 model.

    Bravo, Apple. Bravo.
     
  2. Macman45 macrumors demi-god

    Macman45

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    #2
    I'd like to know how this works. I've insatlled and configured 2 of the new 21.5's, and there are no visible ventilation slots at the top like the old Imac had.

    Underneath there are. I'm guessing that intake is one side, and outlet the other? My maxed out BTO ships January, and it will be put to hard work right away....It's good to know they don't heat up like the old ones...My current model ( 2011 3.5GHZ i7..Maxed out) does heat up on the top quite a bit. This is evident in multitasking ( Aperture HB VLC etc.) and it really becomes a heating system when running X-Plane.
     
  3. Chihawk725 macrumors member

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    #3
    I just wanted to say I fully agree. Apple loves to toot it's own horn, how has it missed out on the chance to do so in the case of the amazing new cooling design?

    The 2012 iMac is an ice cube compared to the 2011 and previous models, how did this not get a diagrammed full explanation at the most recent keynote or on their website as did the screen and fusion drive upgrades?? Even the macbook pro models have on their sites the new asymmetrical high efficiency fan designs that made them run quieter/cooler.
     
  4. Minxy macrumors member

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    Nov 17, 2012
    #4
    Hi William. Can you say whether your iMac has the 768GB SSD or is using a hard drive?

    I imagine iMacs with SSDs have much less chance of overheating because they don't have a bulky hdd. But what I'd like to know is if an iMac with hdd /fusion drive being used for something processor intensive like a full-fat game run hot.

    I hope you don't mind me asking here as I didn't want to start a new thread: how noisy is an iMac with Hdd or fusion drive with the hdd in use?
     
  5. SOLLERBOY macrumors 6502a

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    #5
    Mine is the same, very cool.
     
  6. steve119 macrumors 6502

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    #6
    Same here, and the icing on the cake? its also very very quiet :D
     
  7. MacCruiZe macrumors member

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    Dec 13, 2012
    #7
    Download a fan controller and crank that baby up to 4k rpm! I was amazed how powerful the fan in this thing really is.

    I have not done anything with it yet to even cause the fan to come to an audible level during use, but it's nice to know it's capable if I need that extra cooling.
     
  8. Ddyracer macrumors 68000

    Ddyracer

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    #8
    How's the speakers? Some say it's worse than their old 27.
     
  9. simsaladimbamba

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    #9
    An SSD might be cooler than an internal HDD, but not by 50 K or so. My HDDs (2.5" and 3.5" always ran at 40 to 50 ° C, thus they play a small part in heating the computer, especially if the CPU and GPU can get much hotter under load.

    Btw, if a computer OVERheats it shuts itself down, if that computer is using modern chips, like current and past Macs have done so.

    Hell, even my 2004 AMD PC would shut down, if it got too hot.
     
  10. Arman macrumors regular

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    #10
    Agree, very surprised by the cooling feature especially with the teardowns showing such a small cooling apparatus. I think this has a lot to do with redesign of the iMac around a more laptop like logic board. The only heat I ever feel is at the vents on my 27", otherwise, I agree the rest of the case feels cool to the touch.
     
  11. WilliamG thread starter macrumors 604

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    #11
    I have a regular 1TB Seagate drive in there. I'm externally booting via a Thunderbolt SSD. The internal drive is surprisingly quiet in use. When I turned my iMac on, I actually thought Apple had sent me an SSD model by mistake!

    ----------

    That's because they are. Not horrible, but nowhere near as good as the outgoing models.
     
  12. JustMartin macrumors 6502a

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    #12
    And there's a thread here somewhere full of people saying that a cool iMac is physically impossible. And that people who had iMacs that weren't melting couldn't have been testing them properly.
     
  13. Mac2133 macrumors member

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    May 31, 2012
    #13
    Writing to say I completely agree. My iMac is a fully loaded 2012 27" iMac (i7/32gb RAM/ 3tb Fusion / 680MX). And you're right, after hours of using Photoshop, Nikon Capture NX2 and Lightroom, it's NOT EVEN lukewarm. Anywhere on the surface on the back. Just some warm air coming out the vents in the back. And, yes, it is pin-drop silent, even when it accesses the hard-drive portion of the Fusion drive. :)
     
  14. chevalier433 macrumors 6502a

    chevalier433

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    #14
    There is not any heat issue with older iMacs 2009 and newer.I don't think you can judge a cooling system from how hot is the aluminum chassis.Pls can you post temperatures idle medium and full load.
     
  15. WilliamG thread starter macrumors 604

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    #15
    We never said there was an "issue" with the older iMacs running hot (or feeling hot). THAT said, the glass of the LCD was also very hot, and that can't be good for the panel, right? With the 2012 iMac, my LCD/glass is room temperature.

    Sorry for the mix of F and C, but that's how I roll:

    Idle temps for my 3.4Ghz i7 = 37C (room temperature is a warm 73F)
    Idle temps for the Geforce 680MX 2GB = An impressive 35C

    I'll get some full load temps later.
     
  16. All Taken macrumors 6502a

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    #16
    I would like to see a comparison between the 2011 and 2012 iMac temperature wise. All of the people saying it 'feels' cooler, ice cold etc etc compared to the 2011 model - be reminded of this, the case acts as a large heat sink which is great, if it feels warm the aluminium is absorbing and effecting that heat generated very well indeed. If it feels cold, well the heat is building up somewhere and unless it's all coming out behind the stand i'd be a bit concerned as to where it is residing.
     
  17. MegaSignal macrumors 6502

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    #17
    Elegantly simple.

    Looking at the tear-down pix, it really appears to be a fascinating way to cool the entire system down all at once with only a single fan. It would appear that the fan draws centrally from within the computer; because the vents are only located at the bottom of the structure, this forces the intake air to pass and subsequently cool all of the internal circuitry; the exiting air is then passed over two heat exchangers which are piped directly from the CPU and GPU; because this air is relatively cooler, both the CPU and GPU are cooled sufficiently. Thus, all heat is forced out of that little grid in the back of the iMac. Talk about simplicity!
    The only thing that surprised me was that it doesn't look to me that the engineers opted for the asymmetrical fan blades, but, everyone's saying that the machine is whisper quiet so it probably wasn't needed; just my observations...
     
  18. DerekS macrumors 6502

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    #18
    Agree with this thread! The cooler temperature is a great new feature, and one that will probably reduce LCD/HDD problems over time.
     
  19. chevalier433 macrumors 6502a

    chevalier433

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    #19
     
  20. Minxy macrumors member

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    #20
    Pin-drop silent? That's really good to know. Having switched from a LOUD pc to a Macbook Air I have loved the speed of the SSD and the quietness of it. I thought I'd never go hdd again but now iMac is finally out I can't justify paying the very high price of the 768GB SSD, and I have been worried that that the hdd version would make it just too noisy.
     
  21. xgman macrumors 601

    xgman

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    #21
    Run a memory tester on the new imac and prepare for the vacuum cleaner sound. I was amazed how loud the fan can get, but only happens under very heavy stress thankfully.
     
  22. Arman macrumors regular

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    #22
    Yes, most likely those of us who are remarking about the quietness of the system are not over stressing the system although mine stayed pretty quiet through some semi-heavy aperture work (exporting batches of 100 to 200 raw to jpeg files). The only time I have heard the fan and it wasn't very loud at all was running the 32bit Geekbench benchmarks.
     
  23. WilliamG thread starter macrumors 604

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    #23
    Oh yes memtest definitely stresses the system and causes the fan to spin up, but it's not an obnoxious sound. No high-pitched whine.

    Right. I didn't hear any fan speed-up during a Diablo 3 session.
     
  24. macdudesir macrumors 6502

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    Jan 16, 2011
    #24
    My 2011 27" iMac is at 30C on the CPU and the GPU is at 39C idling right now, although about 20 minutes ago i was doing some photo work...ambient temp. is a fairly cool 68F. It does feel pretty warm on the top but actual temps are cool. Only had the fans speed up of their own accord once on this iMac, and that was trying. I think the highest the CPU has gotten is 62C. Although it was burning hot on top lol. :p i too am curious to know what the internal temps of the 2012 iMacs are under load.
     
  25. joe-h2o macrumors 6502a

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    Jun 24, 2012
    #25
    The exhaust vent is under the hinge, and there's a single fan that pumps air out of there at a fair old clip. The air intakes are on the bottom.

    I have the i5 with 680MX and I've been running it at high power for hours in Planetside 2 - you can definitely hear the fan at high load, but it's pretty quiet (practically silent compared to a MBP fan), and it's almost totally silent when at low load.

    The back of the machine is hardly even warm after hours of heavy gaming (planetside 2 is no slouch and taxes the CPU and GPU heavily), except around the exhaust vent as you would expect.

    It's remarkable.
     

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