Intel Mac Mini fan goes insane by graphic intense moments

Discussion in 'Mac mini' started by RandomPuppy, Jun 25, 2008.

  1. RandomPuppy macrumors newbie

    Jun 25, 2008
    Hi. Long time reader, first time poster.

    So I've bought an Intel Mac Mini 2.0 Core 2 Duo (GMA 950) a few months back that I am using as an HTPC in my living room. There is one problem: When there are graphic intense stuff going on, on the screen, the fan is increasing in speed from idle 1500 rpm to like 4500 rpm. This is way to high for a quiet desktop computer and also to have in the living room when watching movies.

    This is my experiences: I have a full hd LCD samsung television hooked up to the mini. When I'm outputting 720p to the tv, the fan is quiet since there are less surface to render and send to the tv. When I am cranking up the resolution to full HD, 1080p, the fan immediately kicks off since there are more stuff to render.

    Also, I'm running osxbmc as the media center application and the experience there is that after a few minutes fiddeling around in the menus the fan is increasing in speed and becomes very noticable. This is very annoying.

    After searching in various forums on the net, there has been som, in my opinion, poor solutions to this problem. One is to use smc fan control, but that just delays the inevatible.

    What I want is that the fan should be put to a static speed, lets say 3000 rpm at all time and not be adjusted by some intelligent software in mac os x that says when the fan is supposed to kick in or not.

    Also I have tried to fix with the AppleBlowrer.kext file in the library without any good results coming our from it.

    I cannot be alone with this problem. My basic question is: How can I manually set the fan speed to a certain rpm? There has to be some software out there where you can bypass the SMC.

  2. netdog macrumors 603


    Feb 6, 2006
    Unless you want to cook your Mini, just leave it be. Apple's engineers know what they are doing, and they know the hardware tolerances far better than you.
  3. nickf macrumors member

    Oct 2, 2007
    I don't think fiddling around with fan speeds is a very good idea, tbh.

    The only thing I can suggest is can you improve the ventilation around your mini at all?
  4. RandomPuppy thread starter macrumors newbie

    Jun 25, 2008
    Well it should be up to me if I want to cook my mini or not. There must be a technical way to set the fan to a manual speed. And of course, if I notice that the temperatures of the components are way to high I will reset the fan control system to default.
  5. RandomPuppy thread starter macrumors newbie

    Jun 25, 2008
    Hi. Yeah I was thinking of that too. And I think the ventilation is the issue here. The other day I removed the cover and started up the mini and after that I ran the tests I usually run to angry up the fan and the fan was quiet. So that leads me to some conclusions:

    1) I can run the mac mini without the cover but that would suck in too much dust and clog up the mini.

    2) I can drill ventilation holes in the enclosure , although I think that will not be very efficient.

    3) I can buy one of those cooling plates you put under the computer so it cools down. Question is if this will cool the mini down or not since those plates are designed for laptops.

    Another thought about how the cooling works on a mac mini is that you have small holes at the bottom of the mini where air sucks in and the blow out is above the ports at the back.
  6. RandomPuppy thread starter macrumors newbie

    Jun 25, 2008
    Another option I have been thinking about is to cut the wires to the fan and install a resistor on like 150 ohms or so (don't remember how much it should be on right now) . Because basically there are always the same maximum output in voltage to the fan by default. But if you put a resistor in between you can regulate the speed of the fan since it is voltage based and thus have a static speed all the time.

    What I have noticed is that the mini will usually work around 3000 rpm and this is a speed that you barely hear actually.

    Any thoughts about this people?
  7. qtx43 macrumors 6502a

    Aug 4, 2007
    Really bad idea. You'd probably reduce the cooling because the airflow would not be drawn along the path of the hot components, but drawn in wherever you drilled the holes. And so your fans might actually run faster. And the fans are running because the components actually need cooling. Although I'm sure you could rig something up which turns the fans down or off, good luck with that while it lasts.
  8. RandomPuppy thread starter macrumors newbie

    Jun 25, 2008


    Yeah thanks :). It seems clear however that there is not a general solution to my problem so I have to come up with something that can cool the mini in other way without having to fiddle around with the hardware. Maybe to sink it in oil :).
  9. ale500 macrumors regular

    Jul 9, 2007
    But they will move the air around your mini (I think it sucks air from below). It may help
  10. txr0ckabilly macrumors 6502

    May 21, 2008
    Southwest Louisiana

    i've seen that done on a pc mod forum. kept the components at an even 52-53 deg.C but the oil had to run through a recirculating condenser which basically turned the whole thing into an air cooled/oil cooled machine which does nothing for the original problem of noise. ;P

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