iMac 2013 27" temperature/possible underclock?

Discussion in 'iMac' started by dezmen, Jul 16, 2014.

  1. dezmen macrumors member

    Joined:
    May 23, 2014
    #1
    Recently just playing on my iMac 2013 27" with GTX775 using BootCamp and it seems that iMac cooling is worthless. Having 77*C while just randomly runing on game locations and getting 95*C on intensive scenes (even not intensive at all).

    Is it possible to lower the GPU speed to reduce heating? If yes, any guide available? (didnt find one on internet).
    Atm just using Macs Fan Control to boost fan to 100% speed, doesnt help at all. Underclocking should reduce heat from what I know.

    Or maybe knows some way to cool that beast down...
     
  2. mad3inch1na macrumors 6502a

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    Oct 21, 2013
    #2
    Hmm..95 C is technically acceptable, but it is still running pretty hot for what you are doing. Also, just because there is not a lot of "action" currently going on, your GPU could still be working its butt off. Many of the most intense graphics are devoted to rendering 3D models, calculating physics, and rendering textures. If you just walked around the map on Crysis 3 with Ultra settings on, the 775m would probably be reaching its thermal limit and running at 10 fps.

    Either way, your card is still running hot for what it sounds like you are doing. If you have MSAA 4x on and Ultra settings, you probably want to notch down the settings quite a bit. If that doesn't work, then the thermal paste may not have been applied properly. I would take it into your local Apple store and get it checked out.

    Best,
    Matt
     
  3. Ainze macrumors regular

    Ainze

    Joined:
    Feb 28, 2010
    #3
    I disagree. Those temperatures seem very typical, and remember that your fan will dynamically adapt to maintain a safe temperature. Certainly, under clocking won't help, as the fan will just spin slower while keeping the temperatures the same. Temperature is not an indication of load. Your computer will get to high temperatures with anything from a medium load upwards, only the fan speed will change.

    Seriously though, those sound normal to me. I've been running at those temperatures for years on many different machines and never had any negative consequences.
     
  4. dezmen thread starter macrumors member

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    May 23, 2014
    #4
    The issue is that I've lowered settings already, but still playing on native resolution. It's just that game thingy that its settings doesn't really matter on load. iMac is new, ambient temps are 44-50, room is pretty hot tho -_-
    Lowering GPU speed would help a lot I think.

    I'm ok with max fan speed.
     
  5. mad3inch1na macrumors 6502a

    Joined:
    Oct 21, 2013
    #5
    How long do your computers last? I don't know too much about normal operating temperatures for mGPUs, but for most GPUs, anything above 90 is getting really hot. Considering he has set his fan to 100% all the time, an under clock would technically help.
     
  6. joe-h2o macrumors 6502a

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    Jun 24, 2012
    #6
    Totally normal temperature ranges for the iMac. Don't worry about it.

    If you really want to under clock then install Nvidia inspector and manually change the clocks.
     
  7. Ainze, Jul 16, 2014
    Last edited: Jul 16, 2014

    Ainze macrumors regular

    Ainze

    Joined:
    Feb 28, 2010
    #7
    I've never yet lost a computer. Hard drives? Yes. But never the main board and chips. My 2001 iBook is still as good as new, operations-wise, and all (see sig) have been used for a lot of gaming.

    I still maintain that the fans will automatically spin only just fast enough to keep the components at a safe enough level (The fans are coded that way in the firmware. Underclocking will result in the same max temperature, just with slower fans. You would have to change fan behaviour instead, but you already are). The max temperature may seem high to some people, but it's just about ok, and won't go any higher, and Apple don't seem to like their computers getting too loud. True, it's a design choice that some disagree with, but again, does do the job.
     
  8. Dirtyharry50 macrumors 68000

    Dirtyharry50

    Joined:
    May 17, 2012
    #8
    If your GPU was operating outside of spec, it would shut itself off to prevent damage.

    Don't worry about it. You don't need to be screwing around with the clocks. It is designed to take care of itself if you just let it. ;)

    Now, if you had a problem with the GPU shutting itself off then I would recommend contacting Apple, etc.
     
  9. irnchriz macrumors 65816

    irnchriz

    Joined:
    May 2, 2005
    Location:
    Scotland
    #9
    You may want to consider Air Con, your ambient temperature is pretty hot and it will impede the cooling of any computer.

    Plus if it blows up Apple can tell you to bugger off as the published operating temperature is:

    Operating temperature: 10° to 35° C (50° to 95° F)
    Relative humidity: 5% to 95% non-condensing
     
  10. h9826790 macrumors G3

    h9826790

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    Apr 3, 2014
    Location:
    Hong Kong
    #10
    This is just the reading of your monitoring software, not the real room temperature, right?
     
  11. Mac32, Jul 20, 2014
    Last edited: Jul 25, 2014

    Mac32 macrumors 65816

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    Nov 20, 2010
    #11
    To offer some useful advice:

    1: The iMac is a compact, closed system. If the CPU and GPU is running at near max temperature regularly for long periods of time, that will most likely shorten the internal components' lifetime. The HD is particularly susceptible to heat, and if it hits 60 C+ that's not good. Occasional gamers (who doesn't overclock) shouldn't worry too much. Btw. 77 C is fine.

    2: You can reduce CPU heat with 10 C. Just turn off turbo boost in Windows (set max CPU performance to 99% in Power Options). Don't bother with underclocking.

    3: Use Macs Fan Control for higher static fan speed = more stable temps. (2000-2400rpm depending on the game. Max rpm 2640 shouldn't not necessary, just more wear and tear.) Especially demanding games like Crysis 3 will max out the GPU at around 82-85 C no matter what AFAIK. I overclock my 680MX, and still keep the GPU around 80 C. Apart from that, get air condition.
     
  12. bennibeef macrumors 6502

    Joined:
    May 22, 2013
    #12
    About running fans all the time 100% this is what I learned:

    I have a 2011 Macbook pro which has not had any problems if its gpu but I did not want anyhting happen to it. Well I thought I run it cooler and just let the fans work through at high speeds.

    At first this seemed like a good idea and did this for a couple of months. Then I installed Yosemite on a another ssd and I thought - well I'm running no extra fan speed on yosemite and that thing is actually cooler right now and thank good not that noisy anymore.

    Then I used Mavericks again which is my main system, turned off the running fans or turned them down massively (and reactivated the normal running curve) and the temps where going down again. I always had about 55-60 °C and with slower running fans I got down to about 50-55°C not doing any different task and no other time - like just changing it and minutes later.

    I think its not the best idea in this fan design to keep them running 100%. Maybe the heatsink does not even have the chance to give away the heat to the air or the heated air gets kinda stuck. Just my expierence with messing with the fan control for a static running fan
     
  13. dezmen thread starter macrumors member

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    May 23, 2014
    #13
    Haven't find a way to underclock gpu :confused: Got newest Nvidia drivers and AfterBurner, which doesnt allow me to change clocks :(
     
  14. mmomega macrumors 68030

    mmomega

    Joined:
    Dec 30, 2009
    Location:
    DFW, TX
    #14
    I haven't had an issue with a late 2009 27", a 2010, a 2011, a 2012 nor the 2013. I used to think the same thing until I had to "train" myself to not care about temperatures so much.
    All of the machines listed are fully operational to this day and are used and worked 10+ hours a day x 4 days.

    Just let the machine do what it is supposed to do, I was in the mind set that I somehow knew better than the people that designed the thing.

    The difference between my wife's computer and mine from 5 years ago?
    I ran fans, monitoring tools, spent some portion of time trying to "keep things cooler" etc etc. She just used the machine how she wanted and the iMacs both perform exactly the same 5 years later as when we got them.

    Even on my 2013 I fell back into the "I need to run some sort of monitoring software"... No, I don't.
     
  15. Mac32 macrumors 65816

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    Nov 20, 2010
    #15
    You make some good arguments, but what if your wife is just checking her email, writing some documents and browsing the Internet - and you are playing lots of demanding games and overclocking the GPU? Different uses produce different results. I think we all agree on people playing games occasionally shouldn't worry (or using the iMac for regular stuff like Office, Internet and movies), but if one is constantly pushing the iMac to the max and even overclocking the GPU - then one should be a bit more careful. There are plenty of people here posting about damaged GPU and similar issues with their iMacs.

     
  16. joe-h2o macrumors 6502a

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    Jun 24, 2012
    #16
    Please link to a thread where someone has damage to a Late 2013 or 2013 iMac GPU due to heat.
     
  17. Ainze macrumors regular

    Ainze

    Joined:
    Feb 28, 2010
    #17
    There are hundreds of thousands of these machines out there. Even with a teeny tiny fail rate, you'll be able to find "plenty" of examples of damaged GPUs. In fact, it would be odd not to (Even new components straight out of the factory have a small fault rate associated with them). You have to remember that people usually only post when there's something wrong. You'll never see thousands of "everything's still fine" forum topics.

    Just a fact of statistics with large numbers, coupled with the human tendency to notice bad things more than good things.
     
  18. Mac32, Jul 23, 2014
    Last edited: Jul 23, 2014
  19. dezmen thread starter macrumors member

    Joined:
    May 23, 2014
    #19
    Still looking for a tweak. Summer is very hot here, especially in my room, so I'm a bit worried about my iMac while playing TERA Online.

    [​IMG]

    Those are idle/city sitting temps on EU server (dunno why but NA server got lower temps yolo). In dungeon it may raise up to 95*C. So I'm looking for a guide to lower the GPU and CPU clocks without lowering voltage, or if there is a tool to do it automatically...
     
  20. h9826790, Aug 4, 2014
    Last edited: Aug 5, 2014

    h9826790 macrumors G3

    h9826790

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    Apr 3, 2014
    Location:
    Hong Kong
    #20
    No need to worry. 95 is within the limit, yes, it may sounds very close, but surely not excess yet. If the CPU really approaching overheat, it will thermal throttle itself automatically, after that, it may shut itself down (but still no damage yet). If you never experence any thermal throttling, that means your iMac is not even close to any thermal damage.
     
  21. dezmen thread starter macrumors member

    Joined:
    May 23, 2014
    #21
    I dont need to be worry, just need to lower temps via underclocking :p I dont want to my iMac work at such temps. Big thermal on daily basis is wrong for hardware.
     
  22. Ainze macrumors regular

    Ainze

    Joined:
    Feb 28, 2010
    #22
    True, but you're not on 'big thermal' yet. 95 is normal.
    And under clocking won't change your fan behaviour, which is set to keep your iMac <=95. If you really want it cooler, set your fan to max or otherwise change the firmware settings. This however WILL burn out your fan faster.

    TL - DR? Your computer will last longer as it is.
     
  23. Mac32, Aug 5, 2014
    Last edited: Aug 5, 2014

    Mac32 macrumors 65816

    Joined:
    Nov 20, 2010
    #23
    Lol, you're perfectly fine with temperatures regularly near 100 C in an expensive closed, compact system, where all the various components are crammed together - but yes turning up the fan speed is bad. Ok...
    (Again, hitting 95 C occasionally isn't something to worry about.)

    To OP: If you still want to underclock the GPU (shouldn't be necessary) - use MSI Afterburner. Otherwise, get air condition in your room. That's your options, period.
     
  24. dezmen thread starter macrumors member

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    May 23, 2014
    #24
    I tried to use it, it just blank and doesnt even show current settings.
    Drivers are 337.88.

    To previous user:
    And no, I don't need blond answers like 95 temps are fine. Leave it to kids ^^
     
  25. Mac32, Aug 5, 2014
    Last edited: Aug 5, 2014

    Mac32 macrumors 65816

    Joined:
    Nov 20, 2010
    #25
    MSI Afterburner works fine here (same driver version with 680MX in Windows 7). My iMac is not available to me right now, so I can't be more specific. I would recommend reading a pdf manual for Afterburner, maybe you haven't enabled some setting or something..
     

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