What are good temps for a 2008 24" iMac?

Discussion in 'iMac' started by AppleZwei, Jun 18, 2010.

  1. AppleZwei macrumors member

    Sep 12, 2008
    What are good temps to be seeing in iStat Pro? Also, does the use of the fan control in iStat Pro damage your fans over time, or cause any other harm to my system?
  2. noobsauce macrumors member

    Mar 23, 2010
    You don't have to worry about the temperatures. If your mac is overheating it will shut down.
  3. AppleZwei thread starter macrumors member

    Sep 12, 2008
    I think otherwise. I work at an Apple store, and am working on my ACMT training. I know for a fact that temp can affect performance, even before shutting down.
  4. AppleZwei thread starter macrumors member

    Sep 12, 2008

    Attached Files:

  5. flopticalcube macrumors G4


    Sep 7, 2006
    In the velcro closure of America's Hat
    What you are looking at is iStat Menu. That is not iStat Pro, the widget.
  6. AppleZwei thread starter macrumors member

    Sep 12, 2008
    Ahh I see what you're saying. I was referring to it that way because there is a free version of what I'm using, or at least used to be.
  7. TMRaven macrumors 68020


    Nov 5, 2009
    Your temps are fine, but the fans are revving up pretty high, I'd be annoyed at the white noise myself.

    Having the fans at high rpm at all times won't really damage the fans-- it might have the smallest percentage of shortening lifespan, but not that much. They are only mechanical anyways, no software involved with them.

    I'd prefer SMC fan control to adjust my iMac's fan settings. For instance, I have my i7 iMac's fans set at 940rpm cpu (default) 1100 hdd (default) and 1300 gpu (+300rpm from default). After lots of playing around, I found that settings to be the best bang for the buck. It doesn't affect my fan noise one bit, but it lowers my gpu's temp a whole 8c.
  8. noobsauce macrumors member

    Mar 23, 2010
    It may affect performance, but I don't think it will physically damage the hardware or cause any other long term damage
  9. DoFoT9 macrumors P6


    Jun 11, 2007
    105c cut off for that CPU I believe. Nothing to worry about if it is below that.

    I get temperatures of about 50 idle and up to 65 under load (once the fans rev up), which is fine.

    These 'performance issues' you talk about do not come into effect dramatically until you get near TjMax, so I wouldn't worry too much ;)
  10. aki macrumors 6502a

    Mar 2, 2004
    There are lots of very informative threads on this topic. Here is my considered view for what it's worth.

    Firstly, yes iMacs do run on the hot side. They are pretty cramped (yes even the 27") and designed to be svelte. That has a cost.

    Second, yes they get hot to the touch. This is most certainly by design. Touching your iMac tells you nothing except that the heat dissipation is working well. If you want to know what's going on inside, which is the point, use iStat or similar.

    Third, for normal use, the iMac does not require user intervention. This begs the question "What is normal use"? Here's my take. If you upgrade your hardware regularly, don't worry about temps. If you want or may want your iMac to last into the 3 to 5 year range, you should give it a thought. If you use your iMac mostly for email and websurfing and writing papers, forget about temps. If you do marathon gaming sessions, if you often game in bootcamp Windows, or if you do video processing or other "heavy lifting", you should give temps some thought.

    Fourth, most people who worry about temperatures worry about them needlessly; see point three above.

    Fifth, if you do use your iMac for heavy work or often use Windows and do want your machine to last a bit longer or at least know what's going on, the current prefered solution (imo) is iStat or Temperature Monitor or similar, which will give you temps in the menubar or in the Dashboard (OSX side only), and smcfancontrol, which will let you manually set minimum fan speeds (the setting can only be done from OSX, although you can have the fan speed settings carry over to a bootcamp Windows session provided you do a restart and don't switch off the iMac).

    Sixth, if you are setting fan speeds and looking at temps, what should you be looking for? The GPU and CPU are precious and expensive to replace obviously but they are also rated for quite high temperatures. The iMac is designed to shut itself down before you get to that point. What is rather more fragile is your internal HD. High temperatures don't kill HDs immediately, but they do reduce lifespan/increase failure rates. Of course you should be timemachining or similar anyway; but replacing a HD is tedious and stressful and can be very inconvenient. Again, having given due consideration to the points above, I think it's good to set speeds to keep your HD temps in the low 50s C. Under 50C is fine, over 55C is bad, in between is, well, reasonable given what the iMac is. (I should note when I talk about temperatures here I'm talking about high temperatures suistained over a period of time. Spikes in temperature, when you are transcoding a youtube clip or something, that's not worth being concerned about. I'm thinking here about all-night Crysis sessions or whatever.)

    Seventh, and final point. Environmental conditions play a role (more than I originally thought). Depending on where you live, ambient temperatures will have an effect - I'm in Japan and temps are clearly higher in summer than winter inside the iMac. Also, if you live in a dusty environment, it's not a waste of time to dust around your machine and desk regularly - your fans will suck up that dust over time.

    Eighth and actually final point. External fan solutions sound better than they may actually be. I'm not an engineer of any description, but I have read authoritative-sounding accounts of how the fans in the iMac are carefully and cunningly placed so as to maximize efficiency, by directing airflows from certain areas to other certain areas over so and so components. Which is to say, it's all a pretty neatly designed system. There used to be mods around where people would carve holes in the backs of their G5s (this is in the plastic era), and electrical-tape fans on there or what have you. Bad idea (generally speaking) - it just messes with the airflows that some team of very clever Apple engineers burnt countless nights laboring over. Or something. I'm being verbose, the point is, placing little desk fans at the base of your machine or pointing your fan at the air vent in the back might look like its helping - hey, it's cool air, right? - but it may or may not actually be that simple.

    Ok I'm done. Good luck! :)

    PS Ok I lied about being done - if you do elect to use smcfancontrol, it's generally better to trying uping all three fans a small amount than one fan a lot. Again, they are designed to work in concert.
  11. DoFoT9 macrumors P6


    Jun 11, 2007
    ^^ some nice points in there, i do not agree on the temperatures that you recommended but ah well. each to his own ;)

    the iMac i7 has WONDERFUL cooling :D

    and LOL@your long posts
  12. miniroll32 macrumors 65816


    Mar 28, 2010
    I've got a white MacBook, temps for CPU are;

    Ambient - 52c
    Flash vids - 72c
    Handbrake 94c
    QuickTime rendering - 108c

    Trust me, rendering on QuickTime may just as well scorch the desk!
  13. Tomorrow macrumors 604


    Mar 2, 2008
    Always a day away
    Isn't this a bit like the professor asking the students for the answers? :confused:

    Look it up in your book or ask your teacher. You've clearly asked the wrong crowd.

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