GPU - too hot?

Discussion in 'iMac' started by virginblue4, Feb 19, 2015.

  1. virginblue4 macrumors 68000

    virginblue4

    Joined:
    Apr 15, 2012
    Location:
    United Kingdom
    #1
    Hi, I have a late 2012 27" iMac with the top processor and top GPU (680MX 2GB) and 24GB RAM.

    I installed The Sims 4 a couple of days ago and my GPU diode is getting up to 92C! The fans kick in enough to drop it by 5-10 degrees and then they slow down and the process repeats. Not causing any problems whatsoever, just wondering if this is potentially bad for the GPU?

    I assume not, otherwise it would shut itself down. The fans only go to around 2000rpm for around a minute, I know they are capable of going much higher. So, nothing to worry about?
     
  2. Traverse macrumors 603

    Traverse

    Joined:
    Mar 11, 2013
    Location:
    Here
    #2
    You are within the operating temperatures of your system. Your Mac will shut itself down if it gets dangerously hot. Playing games leverage the GPU quite a bit.

    ----------

    This quote by GGJstudios explains this well.

     
  3. GGJstudios macrumors Westmere

    GGJstudios

    Joined:
    May 16, 2008
    #3
    It's perfectly normal. Those temps are well within the safe operating range.
     
  4. virginblue4 thread starter macrumors 68000

    virginblue4

    Joined:
    Apr 15, 2012
    Location:
    United Kingdom
    #4
    Thank you both for your replies. I did assume it was normal just panicked a little as it hadn't happened before, but then again I haven't really played any games before.
     
  5. Traverse macrumors 603

    Traverse

    Joined:
    Mar 11, 2013
    Location:
    Here
    #5
    I don't blame you. I was concerned when my first Macbook hit 92 degrees Celsius when encoding some video, but it is normal.
     
  6. thundersteele macrumors 68030

    Joined:
    Oct 19, 2011
    Location:
    Switzerland
    #6
    Thanks for asking this question.

    According to a few fellow posters here, the 2012/2013 models with 680M/780M are magically silent and never heat up even under full load.

    Of course 92C are still lower better than the 105C my 5k iMac reaches. But it all comes down to what the manufacturers consider safe operating temperatures. A lot of Windows desktop PC builders are worried about anything that reaches 70+...
     
  7. Traverse macrumors 603

    Traverse

    Joined:
    Mar 11, 2013
    Location:
    Here
    #7
    Well 105 IS hitting the limit of overheating.
     
  8. thundersteele macrumors 68030

    Joined:
    Oct 19, 2011
    Location:
    Switzerland
    #8
    I read elsewhere that ATI cards can reach up to 115C...
     
  9. Traverse macrumors 603

    Traverse

    Joined:
    Mar 11, 2013
    Location:
    Here
    #9
    Oh, I wasn't aware of that.

    May I ask what you're doing when it reaches 105 degrees? Playing game? Encoding video?
    I wonder if it's just the 5K iMacs.
     
  10. cynics macrumors G3

    Joined:
    Jan 8, 2012
    #10
    For the most part.

    The cooling design far exceeds the heat the GPU is capable of producing on prior models.
     
  11. thundersteele macrumors 68030

    Joined:
    Oct 19, 2011
    Location:
    Switzerland
    #11
    Playing games in my case.

    One should not forget that heat transfer is proportional to the temperature difference. So, given a fixed cooling solution (determined by the iMac design for example), one possibility to reach better performance is to increase the temperature difference, by allowing higher the GPU to reach higher temperatures. (the better solution would be to use a more efficient GPU, like the 970M/980M).
     
  12. andy9l macrumors 68000

    Joined:
    Aug 31, 2009
    Location:
    England, UK
    #12
    92C as the maximum temperature during a gaming session is not an issue.


    Only the 5K iMacs with the M295X GPU suffer the thermal issue. 105C is deemed to be the upper thermal limit, and the GPU throttles itself at this temperature to keep itself 'safe'.

    I've attached a video of my, now returned, 5K iMac running a game - not even playing - at 1440p with the latest drivers from AMD.

    First notice the speed at which it heats up (video is real-time, no edits), then notice the core clock speed drop 10+%. The clock speed then dips every few seconds, presumably to retain the temperature.

    If GPUs can run safely at 115C in an AIO computer, the M295X didn't get the memo.

    Build: 4GHz i7, 4GB M295X, 512 SSD, 24GB RAM

    https://vimeo.com/116208647

    So, really - 92C is nothing to worry about!

    We should probably avoid another M295X debate in here. Video and things just for reference and to answer Traverse.
     
  13. Alesc macrumors 6502

    Alesc

    Joined:
    Nov 11, 2014
    Location:
    France
    #13
    It seems the CPU also throttles on the Retina...
    See at 2'45":
    https://www.youtube.com/watch?v=tgTMxB-ffjM

    I've run the test on my late 2013 last night, no throttle... It is weird, as the 4790K has only 4W more TDP than the 4771 (84W vs 88W)...
     
  14. Traverse macrumors 603

    Traverse

    Joined:
    Mar 11, 2013
    Location:
    Here
    #14
    Thank you andy9l for the interesting video. I won't hijack this thread by going into a GPU depute, but it is interesting how rapidly that system heats up.

    I wouldn't be overly concerned with 92C, but I would be uncomfortable running at 105C on a regular basis. However, you were running in Windows (presumably through bootcamp) which doesn't have the best drivers, but you say you have all the latest AMD drivers. Is that why you returned it?


    Side Note: I can tell how beautiful the retina screen is based on your video! There was non of that rainbow pixel stuff that usually happens when you film a screen. :)
     
  15. thundersteele macrumors 68030

    Joined:
    Oct 19, 2011
    Location:
    Switzerland
    #15
    This seems reasonable based on intuition, but is wrong. If you have a GPU with a maximal safe temperature of 90C, then it would be very worrisome if it heated up to 92C, and it would trigger a system shutdown. On the other hand if you have a GPU rated for 120C, then 105C would be no issue at all.

    Beyond that, one could worry that a very hot component might negatively affect other components, be it the hard drive, screen, or the solder joints. Here of course one has to trust the manufacturer. The iMac is not a laptop, so there should be enough space to keep things separated.

    Now from a customer perspective, a higher maximal temperature could actually be an advantage, because it would allow to carry away more heat energy with the same fan speed, i.e. more efficient cooling. Of course if the total heat output is larger, which seems to be the case with the M295X, this doesn't help.

    I'm also not interested in another M295X temperature debate, so I will stop here. But saying that temperature A is ok while B is too high, when they refer to different chips from different manufacturers, is not meaningful!
     
  16. andy9l macrumors 68000

    Joined:
    Aug 31, 2009
    Location:
    England, UK
    #16
    GPU - too hot?


    No problem.

    The video was on Windows, but the same temperature rise occurs in OS X - there's a benchmark thread in this forum with examples.

    The screen and iMac as a whole unit was undeniably magnificent. For that very reason, I'm waiting for the next gen rather than settling for a low-end 2013 Mac Pro with a 4K screen.

    I returned it because the GPU performance wasn't up to my expectations, and the fan kicked in too frequently - something that would only ever increase as the Mac aged and was pushed harder by future OS updates, apps, etc.. It was basically a louder, hotter 2013 iMac with a better screen.

    Also, an Apple technician told me the temperatures we are seeing are "not safe for anything". But who knows if that's true. That said, it's weird that none, literally NONE, of the refurbs so far have contained the M295X.

    Anyway, it is what it is. It's arguably a first-gen product, and I'm sure it'll be improved.
     
  17. virginblue4 thread starter macrumors 68000

    virginblue4

    Joined:
    Apr 15, 2012
    Location:
    United Kingdom
    #17
    Out of interest, what are the operating temperatures for the CPU & GPU that are in my Mac? (They are in my signature).

    It hit 95C just now. Is it safe to play this game for hours on end at these temperatures?
     
  18. GGJstudios macrumors Westmere

    GGJstudios

    Joined:
    May 16, 2008
    #18
    If you're not already doing so, use iStat Pro (free) or iStat Menus ($16) to get accurate readings of your temps, fan speeds, etc., rather than relying on your sense of touch or sound. A forum member has posted a copy of iStat Pro that has been "tweaked" to enhance compatibility with recent OS X versions. You can download it here.
    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. (GPU Tjmax may vary with specific models.)(Source: Intel)
    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.
    The fans in Macs are always on when the Mac is on, spinning at a minimum speed which varies by Mac model. 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 on the back of the computer. Make sure the vents remain unblocked to allow your computer to perform at its best. For Flash-related issues:
     
  19. Traverse macrumors 603

    Traverse

    Joined:
    Mar 11, 2013
    Location:
    Here
  20. quagmire macrumors 603

    quagmire

    Joined:
    Apr 19, 2004
    #20
    While those temps are within safe operating parameters, I would still buy iStat Menu's and manually adjust the fan speed( especially if you plan to keep the computer beyond the AppleCare warranty if you bought that). While the heat may not damage the GPU, CPU, etc the heat build up within the case may damage the LCD display, etc( as seen with my parents Late 2009 iMac LCD panel gaining vertical lines which a lot of people suspect is due to the heat).

    When I play X-Plane 10, I set the fan to 2600 RPM and the 780M is around 62-66 C. If I leave it to Apple's stock fan control, temps go up to 82-85 C.

    Apple values quiet operation above all else. They will let heat build up in order to keep the machine quiet. And IMHO, just because the temps at 90 C is within parameters, doesn't mean those temps are good to begin with. If your cars engine temperature began to run right below the redline, would you be comfortable with that and go, " It's still within safe parameters"?
     
  21. Coldmode macrumors regular

    Joined:
    Mar 10, 2010
    #21
    95C is fine and it's designed to work like that for long periods. If you want you can use smcFanControl to set the fans to their max RPM before you start playing. That will make the computer stay cooler for longer. It's much harder for the fans to cool the GPU once it's already hot than it is to keep it cool from the start.
     
  22. virginblue4 thread starter macrumors 68000

    virginblue4

    Joined:
    Apr 15, 2012
    Location:
    United Kingdom
    #22
    Thanks, currently using the free version of iStat. Would you recommended increasing fan speed as mentioned below?

    Sounds reasonable. Will this result in premature fan failure? I suppose if it does, it's cheaper than premature GPU failure!

    Might give this a go, thanks :)
     
  23. GGJstudios macrumors Westmere

    GGJstudios

    Joined:
    May 16, 2008
    #23
    While others may disagree, I recommend using a Mac as it was designed to be used. I've never used fan control software or other cooling methods other than that which is built in to my Macs, and I've never had any problems. Yes, the fans spin faster under heavy workloads, but that's what they're designed to do.
     
  24. chabig macrumors 68040

    Joined:
    Sep 6, 2002
    #24
    My recommendation would be the opposite. If you're not using those things you're doing it right.
     
  25. matreya macrumors 65816

    matreya

    Joined:
    Nov 14, 2009
    #25
    Yes, do be in the dark... just let your Mac run until it dies, without knowing for example, that your fan has been inactive for a few months during summer..

    And increasing the fan speed from 1200 to 1800 RPM keeps things a wee bit cooler this summer (I'm in the southern hemisphere) for my Retina iMac

    I only discovered thanks to iStat Menus that the elevated temps of the SSDs inside my Akitio thunderbolt enclosure lead me to find it had it's quiet fan die on me.

    So, it's a question of whether you want to know what's going on inside your Mac, or if you prefer to be ignorant, and then wonder one day why your Mac is dead :)
     

Share This Page