iMac Temperature

Discussion in 'iMac' started by Oz86, Jul 3, 2008.

  1. Oz86 macrumors newbie

    Apr 14, 2008
    Can someone tell me whether my iMac is running too hot. I'm starting to get a little paranoid about this.

    Temperature readings from iStat
    CPU - 38 C
    GPU - 51 C
    GPU Diode - 50 C
    GPU Heatsink - 49 C
    Ambient - 23 C
    Mem Controller - 42 C
    Airport Card - 48 C
    HD Bay - 50 C
  2. eji macrumors 6502


    Jun 8, 2004
    Inland Empire
    Is it the aluminum model?

    I have the 24" 2.8GHz model and it regularly runs at about 50 degrees for the CPU and 55 for the AirPort card. HD temps are usually between 45 and 50.

    I downloaded smcFanControl and use it to manually adjust the cooling depending on the task. The upper left corner, on the top, gets egg-fryingly hot at times. More than anything else, I try to keep the temps down to limit wear and tear on the HDD.

    In any case, your temps look pretty good.
  3. Oz86 thread starter macrumors newbie

    Apr 14, 2008
    It is the Aluminum model. I've read that it does get hot as it's dissipating the heat from the hard-drive.

    Could you suggest some fans speed settings for smcFanControl?

  4. imac123 macrumors regular

    Apr 26, 2008
    when you download smcfancontrol, move the marker on each fan control setting to about 1/4 down and see what that does. I bumped up the optical drive fan just a little, the cpu fan a little more, and the HDD fan the most (up to around 2800 or even 3100 if it gets too toasty).

    As your ambient temperature varies (in winter or summer), your computer temps will vary too, so sometimes your fans will have to work harder and sometimes they wont
  5. Colonel Badger macrumors 6502

    Jun 30, 2008
    Stupid question, but surely the computer is doing this for you anyway (bumping up/reducing fan speed) as needed?
  6. gehrbox macrumors 65816


    Jul 5, 2007
    I compared you figures to mine while surfing the web. Your temps are normal.
  7. imac123 macrumors regular

    Apr 26, 2008
    well that's the main "issue/controversy/problem" that SOME people see w/ iMacs. Some ppl have the opinion that, like you mentioned, the apple engineers are smart enough to make the fan run at adequate speeds, especially when the temps rise and the speeds need to increase. Others (like myself) have the opinion that the main concern in the design/engineering was to have the fans run at the LOWEST POSSIBLE speed in order to keep the machine as quiet as possible while still letting the components survive within their limiting temperatures.

    And sure... most of the time the temps are within limits, but usually they are pushing the upper limits that you really don't want to approach. For example, my HDD gets around 54 deg C without smcfancontrol. Considering most HDD max temps are about 55-60 deg C, I'd prefer to have my HDD stay at around 50 deg C just for "safety". Most ppl agree that prolonged high temps for the HDD result in shorter lifespan in the long run.

    If you left the temps/fans alone, I think you'd be fine. It just gives some of us peace of mind to increase the fan speeds a bit so that temps are more "normal" rather than pushing the uncomfortable limits. The iMac will automatically increase fan speeds when temps get too high... you just have to realize that "too high" reallllyyyy means "definitely too high" whereas some ppl want the fans to kick in more when temps get "kinda too high"... make sense?
  8. Muncher macrumors 65816


    Apr 19, 2007
    I'm very paranoid about this, and because of that, my HDD is at 35 deg C. :rolleyes:
  9. nickf macrumors member

    Oct 2, 2007
    Are you not paranoid about the shortening the lifespan of your fans too? ;)
  10. aki macrumors 6502a

    Mar 2, 2004
    ....yes but fans dont store data :)

    35 is very cold tho i just try to stay under 50
  11. Muncher macrumors 65816


    Apr 19, 2007
    My HDD fan is usually @2114 rpm. My room fan, is on high. :D

    My smc speeds are:

    ODD: 1345 rpm
    HDD: 2114 rpm
    CPU: 1593 rpm

    But generally anything approximating those values will work.

    Wanna take 2 months off your fans' life and have a good time? Use smc to set your fans to full blast! It sounds like a jet engine warming up! :D
  12. emac4ever123 macrumors newbie

    Jul 9, 2008
    I have a 2.8 santa rosa iMac. Usually while just surfing the cpu stays at 45-48 degrees. The powersupply is usually in the 70 degree range. When I am doing heavy work though, according to iStat, the CPU goes up to 63-65 degrees and the power supply in the 80's range! I have used SMC before but when it is in the 63-65 degree rang, putting it half way for all fans brings the temperature down to about 55. Still a bit worried and the GPU runs quite hot too. Any ideas? The applecare is going to run out next month so if something could go wrong, I want to fix it now!

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