Control temperatures iMac

Discussion in 'iMac' started by T-bag, Jan 28, 2011.

  1. T-bag Guest

    Jan 20, 2011
    I'm looking for a fan control program that allows you to set a minimum temperature for the components in an iMac. Is there such a thing? smcfancontrol seems only to let you adjust fan speed manually. Or does the fans still automatically kick in at a critical point?
  2. alust2013 macrumors 601


    Feb 6, 2010
    On the fence
    The fans will speed up if the computer thinks it's getting too hot. I actually use a program called fan control that changes the adjustment curve a bit, and it slows down the fan when it's cooler and has an even curve to how it ramps up.
  3. T-bag thread starter Guest

    Jan 20, 2011
    That sounds like what I want. Wanna run the fans a little more than default, to get the general temp. down. What I meant in my first post is that I'm wondering if smcfancontrol intervenes with the effect of the fans kicking in at a critical point. If you set it to 3000 rpm it will stay there no matter the temp. Is that correct?
  4. mstrze macrumors 68000

    Nov 6, 2009
    Why do you have a need to cool the computer more than the operating system deems necessary for safe operation? Are you overthinking things, or is there an actual reason why you need things to be cooler?

    Macs (and all computers honestly) are designed with fans that operate when they need to. Even, let's say, if you add more internal componants/cards to a computer, the fans will still run when the systems gets too hot. It would just get to that point more quickly than in a 'bare' computer.

    Unless you are physically doing something to the componants or the temperature sensors to a point where they will not accurately be reading any longer, there really isn't a need to mess with fan speeds.
  5. DanielCoffey macrumors 65816


    Nov 15, 2010
    Edinburgh, UK
    smcFanControl says it just adjusts the minimum fan speed so from that I would assume the fans will run faster if the temperature rises enough to require it.

    Apple will have a temperature-vs-speed profile and all smcFanControl should do is raise the lowest point on that profile. Once you get toasty hot, it should just follow the profile until the temp drops back down again, at which point it should settle at the smcFanControl "floor" rather than the default Apple one.
  6. DanielCoffey macrumors 65816


    Nov 15, 2010
    Edinburgh, UK
    @mstrze - there are arguments both ways for and against changing the fan speeds.

    One view is that we should just leave the airflow system the way Apple have set it up since they designed and tested the system and components. The other view is that there are enough stories here on the forums about "cooked" iMacs that folks would like to control the internal temperatures a little more aggressively. It is for those people that smcFanControl was created.
  7. T-bag thread starter Guest

    Jan 20, 2011
    I might be overthinking things, having heard that these machines have heat issues - affecting the screen over time etc.

    Guess I'll just try smc and see what happens when I make it work.
  8. spcdust macrumors 6502a


    May 6, 2008
    London, UK
    I can see what you're trying to do, but my two penny worth......

    I've always used SMC Fan control as I dual boot into Windows 7 for gaming and I'm not convinced the fan control between Windows 7 OS and the iMac is that good (it really runs hot, even without playing any games). Great thing with SMC fan control you can create profiles and once you've selected one, such as a gaming profile, when you reboot into Windows 7 it remembers the speeds you've set the fans and makes a marked difference in keeping the GPU and CPU temperatures down.
  9. TMRaven macrumors 68020


    Nov 5, 2009
    I havn't had any "over time" issues with my screen so far.
  10. Cmd-the-World macrumors regular

    Apr 7, 2010
    How did you manage to do that? Did you arrange any other prefs apart from creating a new profile? :confused:

    I have a number of different profiles however whenever I boot on Vista SMC does not boost the fans.

    Just a thought maybe because I have multiple user accounts under Mac OSX??
  11. MacHamster68 macrumors 68040


    Sep 17, 2009
    if you reach wile gaming the point of heat when the cpu shuts down , i would not think about a fan controller i would say go and bring it back where you bought it as your smc settings are all wrong or none of the fans is working in both cases a fan controller will not solve the problem really

    there is only one exeption when it is necessary to install a fan controller and that is if in your intel iMac has a nvidia card, cool it as much as you can then you have a chance to see the card living longer then 2 years
  12. JamSandwich macrumors regular

    May 19, 2006
    In my experience, if you set the fans to a specific speed and then restart (not shut down and restart), the fans will continue to run at the speed they were at when you exited OSX.

    As for the need, there's definitely a valid question as to whether it's worthwhile. I think it is. I don't get any sense of more than minimal cooling from my machine and it's been through two hard drives. Its temperatures in terms of the processor are probably "within spec."

    I have another few months of Applecare, but at this stage I'm willing to take whatever precautions might help prevent another failure. I'm seriously considering a new machine so I can use the leftover warranty as a selling point.
  13. Stonefly macrumors regular


    Dec 26, 2009
    Nova Scotia
    I have smc fan control on mine. Increased the fan speeds 500 rpm on each fan for normal use and when using handbrake or other cpu intensive programs I increased them 1000 rpm each. I have those 2 settings ready to use plus the default. Before I had this installed just browsing the net my temp would hover around 50C which I found kind of hot for normal use. Now it's around 38C with the 500 rpm increase.

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