Which specs for minimum fan noise.

Discussion in 'iMac' started by Richard Mille, Jun 9, 2017.

  1. Richard Mille macrumors newbie

    Jun 8, 2017
    Hi and apologies for the long winded post. I am hoping someone here can help me with a couple of questions.

    My uses aside from the normal daily tasks are stock trading/research and light games (older games like World of Warcraft, at native resolution).

    Other than adequate performance my most important priority is to have minimum fan noise while doing these activities. I intend to keep the computer for 18-24 months.

    Regardless of other options I have decided to select the SSD.

    Now on my MacBook Pro these activities run fine so I have no doubt that the minimum iMac specs will suit my needs. However the fan comes on with the MBP so my question is is it better to choose the i7 processor and the faster GFX with more memory on it? As a computer idiot my logic is the more powerful components will not have to work as hard and so produce less heat. Is this actually the case or do more powerful components produce more heat regardless of workload?

    My other question is which screen size to buy. Does the 27" iMac have different cooling capability due to its larger size or are both computers the same? The 27" screen is a benefit to me but the extra pixels obviously result in extra GPU (and CPU?) usage so again comes back to heat. I would opt for the 21" model if the 27" meant sacrificing silentness.

    Thanks in advance.
  2. DrDavid macrumors newbie

    Jul 27, 2010

    Bump - anyone have any advice on this?
  3. joema2 macrumors 68000


    Sep 3, 2013
    You are over thinking this. The 2015 and later iMac 27 with SSD is pretty quiet. The 27 screen is much better than the 21.5". I have a 2015 and 2016 top-spec MacBook Pro, plus a top-spec 2015 iMac 27. The 2015 MBP fan spins up at the slightest touch and is fairly loud. The 2016 MBP is a lot quieter. The iMac is quieter than both. If I am doing sustained video transcoding, yes you can hear the fans, but the work threshold to instigate that is much greater than the MBP.

    If you have no problems with noise from the MBP the iMac 27 will be considerably quieter. I personally like the i7 since I do video editing. I don't know if the i5 would be quieter but I tend to doubt it.
  4. Quash macrumors regular

    Sep 27, 2007
    All iMacs will be quiet compared to a macbook pro running under full load.
    The only way to really test this is run them side by side running the same benchmarks.
    Doubt anyone is going to do that.

    The 575m model runs a non K i5-7600 which is more efficient than the i5 K version in the high end and then there is also the i7 which is even less power efficient than the default i5 7600K. If the power efficiency is gonna result in slower running fans remains to be seen. It's all a matter of temperature threshold. Same with the GPU power, the lower clocks and less cores will generally produce less heat when maxed out.

    Noise bothers me a lot as well so, i'm waiting for the first iMac with 580 gpu reports before pulling the trigger.
  5. kblbn86 macrumors member

    Aug 20, 2016
    I bought the base 27" iMac with 256 SSD.

    i5 7500 + RP 570 + SSD coupled with the big body should equal to a quiter pc.
  6. ApfelKuchen macrumors 68030

    Aug 28, 2012
    Between the coasts
    There are a lot of variables that go into heat generation in a computer, as some generations of chips are designed to run on lower power that others. But basically, work is work - the same job demands a certain amount of work. The heat will be generated over a longer period of time on a machine with a lower clock speed. When executing a multi-threaded process, a two-core processor will take longer to execute than the four-core processor - you'll have a shorter burst of heat from the quad-core, maybe a slower "burn" from the duo-core. Either way, the heat has to be dissipated.

    Now, if you're running tasks that are at the upper limits of operation for a "weak" system, you'll likely require sustained cooling, rather than brief bursts of cooling (if fan cooling is needed at all - convective cooling may be enough for brief bursts of activity). But if the tasks are well within the capabilities of the weaker system (and it sounds like yours are), both the weaker and stronger systems are likely to be generating an intermittent heat load - it may be a matter of how long the fan runs, rather than how fast the fan runs.

    It seems like you're comparing a "weaker" computer to a weaker human being - stronger person may not break a sweat doing something that makes a weaker person huff and puff. However, the reasons for that happening are not directly related to the amount of work that was done - it has a lot to do with how well all the body's systems are working - the condition of heart and lungs, blood oxygenation, etc. For all intents and purposes, most silicon devices are going to be in equally good "condition" - it just comes down to speed and muscle mass - two people in equally good physical condition, one working at a slower rate than the other - depending on the task, neither may show any appreciable stress.
  7. Trebuin macrumors 65816


    Jun 3, 2008
    Central Cali
    I spec'd out at i7 with 580, but I'm also running turbo boost switcher pro to disable hyper threading with cuts the volts & the heat on the cpu, & i'm running a fan control to keep the temps below 85C. It spend most of the time with the fans off. maxing out the CPU/GPU has not resulted in going to 100% fan speed yet.
  8. saberfi macrumors member


    Oct 7, 2015
    Aye, I also bought the mid-model, i5-7600 + RP 575 + SSD for these reasons.

    It was not an easy call, as I would've liked the 580, but I was willing to sacrifice a little gpu performance for a pretty much sure-shot quiet/cool combo.

    It's unfortunate that the top model doesn't offer a 65W CPU, as the i5-7600K (let alone the i7) does run hotter than the 7600 under load.

    Remains to be seen whether 91W CPU + RP 580 lead to high enough temps to activate the fans noticeably more, but it is a possibility which I wanted to avoid.
  9. Richard Mille thread starter macrumors newbie

    Jun 8, 2017
    Thanks very much for the replies. Very informative. And thanks ApfelKutchen the explanation helped a lot - I have decided to "max out" the machine based on this as my stock trading applications in particular benefit from the short bursts of power you mention and hopefully the heat difference will be insignificant - the power is never needed for an extended amount of time.

    Thanks again everyone
  10. fathergll macrumors 65816

    Sep 3, 2014

    First report I read is that the 580 is actually very cool and quite. Some initial good news.

    AMD Radeon R9 M295X Core Clock Throttling, Heat, and Performance
  11. ctrlzone macrumors regular


    Feb 9, 2017
    why not the fan-less macbook? now thats what i call silent operation :)
    wow is ancient now, this should be doable for the new macbook.
    or is it going to have issues?

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