2012 27" i7 680MX iMac 100+ Celcius in Bootcamp

Discussion in 'Windows, Linux & Others on the Mac' started by JackTre, Jan 22, 2013.

  1. JackTre macrumors newbie

    Jan 22, 2013

    How much of a concern are high core temperatures in bootcamp? An hour of an intensive game on Windows 7 and my new computer was very hot - not to the touch but internally according to a program called coretemp (each core was around 100C) . Should macs really be running windows?

  2. GGJstudios macrumors Westmere


    May 16, 2008
    It's perfectly normal to reach such temps during extreme gaming, whether in Windows or Mac OS X. The Intel processors used in Macs are designed to automatically shut down to prevent damage if they truly overheat. CPU Tjmax = 105C (221F), GPU Tjmax = 100C (212F) on i3, i5, i7 processors. (Source: Intel)

    If you're not already using it, iStat Pro (free) or iStat Menus ($16) will give you accurate readings of your temps and fan speeds, among other things.

    Unless there is a rare defect in a Mac, most temps are well within the normal operating range, considering the workload being put on it. Websites with Flash content, games and other multimedia apps will put higher demand on the CPU/GPU, generating more heat. This is normal. If you're constantly putting high demands on your system, such as gaming or other multimedia tasks, expect temps to rise and fans to spin up accordingly. It's just your Mac doing its job to maintain temps within the normal range.

    It is also quite normal for your Mac to become extremely hot to the touch during intensive operations. The aluminum body transfers heat more effectively than other materials used in computer casings, so you will feel the heat more. This doesn't indicate that it's overheating and will not harm the computer to be hot to the touch.

    Your fans are always on when your Mac is on, spinning at a minimum of 2000 rpm (for MBPs) or 1800 rpm (for MBAs, MBs and minis). iMacs have 3 fans with minimum speeds in the 800-1200 range. They will spin faster as needed to keep temps at a safe level.

    If your fans are spinning up without increased heat, try resetting the SMC.
    (PRAM/NVRAM has nothing to do with these issues, so resetting it will not help.)

    The intake and exhaust vents are in the back of the computer near the hinge on all Mac notebooks (except the new MBP with retina display, which has intake vents along the sides at the bottom). The iMac vent is a slot on the back near the top of the computer. Make sure the vents remain unblocked to allow your computer to perform at its best.

    Learn about the fans in your Mac
    Apple Portables: Operating temperature

    For Flash-related issues:
  3. simsaladimbamba

    Nov 28, 2010
    There will be further information down or up there shortly, but 100° C is within the specs of the i7 CPUs.

    And Macs use the same internals, slightly modified in some instances, as Windows or Linux computers do, thus Macs can run Windows. If they should is a personal and subjective matter.
  4. Tri-stan macrumors 6502

    Oct 27, 2012
    Is it the cpu of gpu which is running hot, presumably the gpu? So is the fan at max speed or loud. I have read that others with the 180mx have been running much cooler but within mac osx.
  5. JackTre thread starter macrumors newbie

    Jan 22, 2013
    Thanks for your replies. Much obliged.

    ...it was the cpu temperature that was being measured while I was playing a game. One core was at 102C I think - the other 3 cores were near that.

    The fans weren't audible above the sound of a noisy lacie external drive.
  6. Tri-stan macrumors 6502

    Oct 27, 2012
    Ok then at that temperature it is close to the i7 tjmax and fans should be a max speed trying to cool the cpu. I think something is wrong here. In games the gfx is taxed much more than the cpu. You may have to test it to get a better idea of all the temperatures and their true correct readings in osx. I would not trust thoes windows apps.
  7. JackTre thread starter macrumors newbie

    Jan 22, 2013
    Cheers. Was thinking the same about that windows app.
  8. chevalier433 macrumors 6502a


    Mar 30, 2011
    My 2010 i7 in pro premiere cs5 editing sessions more demanding from gaming never exceed 85C windows and os x.Why people said that 2012 is cooler than older models because of back aluminum is cooler?
  9. JackTre thread starter macrumors newbie

    Jan 22, 2013
    So it seems that the fan control under Bootcamp/Windows 7 was not effective. I don't think fan revs increased with heat. Is anyone else having this problem?

    I set the fan manually and the temperatures were much cooler.
  10. mateo124 macrumors regular

    Oct 15, 2011
    100C? Wow, and I'm worried about my temps on my PC ever going above 60C. But with my experience, Macs do seem to run really warm, my 2012 MBP 13" would reach 70C just streaming Netflix. Guess its nothing to worry about, short-term anyway. If its gonna break, it likely would be in the near future, still under warranty.


    I just saw you're other post, I would definitely try to keep the temps below 80C, even if it requires the fans to be at full speed. It can't be good for it to be that warm.
  11. Tri-stan macrumors 6502

    Oct 27, 2012
    Heating like will cause the computer to fail early probably after warantee unless apple care has been taken out. It is not normal for the i7 to run so hot, it is putting out less watts than the 180mx for a start.
  12. cirus macrumors 6502a

    Mar 15, 2011
    What GGJ studios means is that its normal for a mac to run at that temperature, its extremely abnormal for a pc to run 100+ degrees.

    Will it kill the computer to run at 100+ degrees celsius? No.

    Is it bad in the long run? Yes.

    Will the computer shut off? No, it should throttle.

    In any other pc on the market, running at 100+ degrees on the cpu would be called chronic overheating. On a mac its normal.

    With most desktops the recommended temperature for the cpu is below 80 degrees. Laptops anything over 90 is bad.

    Higher temperatures will cause equipment failure in the long run.
  13. JackTre thread starter macrumors newbie

    Jan 22, 2013
    The fan speed didn't increase and that's why it got so hot. There is an issue and I don't know if it's windows and bootcamp or the machine itself. I don't think it's gotten hot enough in os x for higher fan speeds to be required so far. Even under a heavy load in logic pro it has been cool and quiet. Maybe I should test it in os x? Any ideas?
  14. Tri-stan macrumors 6502

    Oct 27, 2012
    The fan is a lower process than the operating system, it just responds to temperature. Example the bios in Windows, which control's cpu temperature. Something is just not right here, a fan which is not running at the correct speed to cool the gpu. I would give apple a call.

    Otherwise you could try benchmarking the cpu in osx and see if the temperature is 100 deg C like I said before. What the system temp during max cpu load reads in osx will be the same for Windows under the same loading. You will find the bottom of the problem once you test it with osx apps.
  15. JackTre thread starter macrumors newbie

    Jan 22, 2013
    Tri-stan, thanks - I'll give that a go tomorrow. If the fans kick in at high temperatures in os x that's fine. I can live without bootcamp.
  16. Tri-stan macrumors 6502

    Oct 27, 2012
    Yes this may show that your iMac is capable of effecntly cooling your cpu. It may also mean that you are just not pushing the performance as far as you think you are in windows. Another simple test in windows is that once you have assessed it in osx flip back to boot camp and under loading or the quoted 100 deg C feel the back vent the air should be super hot. If you can barly feel it also suggests that the cpu is not being loaded to what you think it is under boot camp conditions.
  17. JackTre, Jan 25, 2013
    Last edited: Jan 25, 2013

    JackTre thread starter macrumors newbie

    Jan 22, 2013
    Just to update this thread: I ran some benchmarks in os x, just about managed to get the cpu up to 75C and the fans revved up for the first time.

    I tried a stress test in windows and the fan speed also went up when the temp readings were around "90C" and the fan steadied the CPU cores at around 85C.

    During the stress test the temperatures were very even. In a game they fluctuated quicly and a lot (10C spikes and dips)a lot which I guess explains the 100C readings from the other day.

    Sounds like there's a discrepancy in the way temperatures are being portrayed in the two operating systems but I tried 3 temp apps in windows and they all gave the same readings.

    The air vent at the back never really felt that hot compared to the top of my MBP.
  18. Tri-stan macrumors 6502

    Oct 27, 2012
    75 deg C sounds right for the i7, the temperature apps are just not getting the right readings in Windows. This all sounds right to me I think that your i7 is working well. I will let you know how mine is when it arrives in native osx.
  19. JackTre thread starter macrumors newbie

    Jan 22, 2013
  20. Mac32 Suspended

    Nov 20, 2010
    As I suspected, the i7 3.4ghz CPU runs quite hot. When I play Crysis 1 for an extended sitting, I set the fan to 1900rpm, and the CPU gets up to 84C (max temp).
    That's a bit hotter than I'd like, maybe I'll crank up the fan a little bit more..
  21. Tri-stan macrumors 6502

    Oct 27, 2012
    Do you have the 180mx as well? You know that the heatsnk for both the gpu and the cpu are joined togeather or possibly have a very small gap but I think they are connected. So when the 180mx is processing at max clocks it reduces the ability for the core i7 to cool down given that the base line of that processor is 70-75 deg C alone at a lower fan speed. 75 degrees is a good temperature for the iMac.

    When the i7 is in a good pc case you would not see much difference if the gpu is fully loaded. You may have a problem in the iMac if you maxed both the i7 and the 180mx at the same time, not normal for that to happen during normal use thought possible.
  22. Mac32 Suspended

    Nov 20, 2010
    Good point. Yeah, I also have the 680MX. The gfx card is about 8C cooler than the CPU though. The 680MX seems to go up to about 74-76C at max with very demanding games like Crysis. Of course, playing something like Half-Life 2, the GFX runs 20C cooler.. :)
  23. WilliamG macrumors G3

    Mar 29, 2008
    What app do you guys recommend for monitoring temps in Boot Camp, and being able to change fan speeds?

    (Windows 7 64bit user here)

  24. auhlixer macrumors regular

    Apr 15, 2006
    Philadelphia, PA
    What does it idle at when you aren't gaming?

    Just curious because I have some interest in getting your same iMac :D
  25. insane79 macrumors 6502

    Aug 20, 2008
    Hmmn nice info, i m planning to install windows 8 via bootcamp for gaming on my late 2012 iMac, i am worried about the over heating issues, are you still gaming via boot camp? do you control the cpu & gpu temps with a manual fan app or left it the way it is?


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