Late 2015 Retina m395x GPU die temperature

Discussion in 'iMac' started by Merlin_the_mog, Nov 21, 2016.

  1. Merlin_the_mog macrumors newbie

    Joined:
    Sep 24, 2016
    #1
    Hi,

    I just bought a late 2015 iMac to replace my ageing 2012, and I'm a bit concerned about the temperatures the GPU is running at.
    My iMac has an i7 and the m395x GPU.
    I first noticed it when I was running a few oldish games - I'm not trying to run the latest, just things like Diablo 3 and WOW.
    The fans spin up into action very quickly, and I can feel a lot of heat coming out the back of the iMac.
    I wasn't too concerned at this point, but I decided to install iStat Menus to keep an eye on the temperatures. This is when I noticed that the GPU die was reporting a temperature of around 101 degrees C.

    The strange things is that even when I run these games at lower resolutions with VSync on, the GPU still goes over 100 degrees C.

    I tried installing the Heaven Benchmark to see what effect this had on the temperatures. The temperature seems to go to a similar level whether I run the benchmark on the default (medium) settings, or on ultra.
    By running the benchmark 3 times in a row, the temperature touched 105 degrees C before the fans cut in a brought things down a little. Surely this is seriously hot for a GPU?
    Is this normal for this GPU in the latest iMac? Can anyone else with a similar spec run the heaven benchmark and let me know what GPU temperature they're seeing please?

    At the moment, I'm still in my return window and I'd like to know if this is something I should be concerned about (or not).

    Thanks in advance,
    Steve
     
  2. IngerMan, Nov 21, 2016
    Last edited: Nov 21, 2016

    IngerMan macrumors 6502a

    IngerMan

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    Michigan
    #2
    That seems high, If I watch TV through Safari and my internet provider it runs about 75 C, can you check what watching TV video does? I am sure some more voices can chime in.

    I am only running a 3.3ghz i5 M395

    Edit: after testing bench marks that seems in spec, at least the same for my machine.
     
  3. Samuelsan2001 macrumors 604

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    Oct 24, 2013
    #3
    Sounds like an issue with the GPU cooling take it back to Apple and get them to replace it.
     
  4. Merlin_the_mog thread starter macrumors newbie

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    Sep 24, 2016
    #4
    Thanks - That's what I'm currently thinking.

    I think the m395 with an i5 is likely to run considerably cooler.
    I was hoping someone else with the same GPU (m395x), and an i7 (4Ghz) could confirm what temperature their GPU gets to when running the Unigine Heaven benchmark so I can be sure that I'm going to get something that runs cooler first (if possible). Other than the high GPU die temperature, everything is working great, and the other temperatures (including GPU proximity) all look reasonable.

    I just have everything setup on the iMac and it'll be a pain to have to do that again if they're all like this.
     
  5. Samuelsan2001 macrumors 604

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    Oct 24, 2013
    #5
    People have been using these macs 24/7 editing 4K video for over a year, with no issues yours is definitely not well, I bet they forgot the thermal paste!!
     
  6. IngerMan, Nov 21, 2016
    Last edited: Nov 21, 2016

    IngerMan macrumors 6502a

    IngerMan

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    Michigan
    #6
    Screen Shot 2016-11-21 at 10.04.33 AM-1.png View attachment 673822

    Well I down loaded the Heaven Benchmark test and I got up to 99 C on the 2nd time. I checked my Monity Stat which agreed. The fans were not loud and under 1500 RPM, It did not feel that warm to me. I guess operating temp in 100C is not unusual when gaming.

    Curious Merlin what did you score on the bench mark using i7 M395X?
     
  7. Merlin_the_mog thread starter macrumors newbie

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    Sep 24, 2016
    #7
    I'll post my benchmark in a couple of hours when I get back to my iMac.

    By the way, thanks for checking this. It does make me feel a bit better since mine seems to hover around 100-101 C after 3 runs and it's only once got up to 105 C (very briefly).
    I guess I'd expect the M395X to run a little hotter so maybe this is within spec after all.
     
  8. IngerMan macrumors 6502a

    IngerMan

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    Michigan
    #8
    Yes I ran the bench mark about 5 times in a row. It would get up to 100C by the end of the first run or early in the 2nd. It would then just Hover around 99C , Fans would get in the 1500's but not very loud in my opinion. Nothing seemed stressed running at that temp.
     
  9. macmee Suspended

    macmee

    Joined:
    Dec 13, 2008
    Location:
    Canada
    #9
    I've owned the 2010 and 2014 imacs, as well as a 2014 macbook pro and temperatures into the 90C's and 100C's are normal for these systems under load

    that's not to say they're safe. There's some theories around the forums which suggest that running iMacs that hot for extended periods of time can damage the screen and cause image retention to develop over time.

    But you'll have to chalk ^ this up to being speculation I guess because there's only 6 or 7 well detailed accounts of users getting retention, screen replacements, then retention again, and there's a poll where 22 / 100 people say their iMac developed screen retention over time. Personally I think this is pretty alarming evidence to suggest that we should be worried about image retention and running the device hot, although I think some people disagree with me.

    That said, I believe the 2015s fan can crank up to 2800 RPM, even faster than the 2014s, so if you're really concerned then you can always get that smcfan app and force it to 2800 RPM as you game. I have no idea if forcing the fan to ramp up like this is bad for longevity of the product. I assume it will cause some wear because my 2010 and now my 2014 fans developed this annoying rattling noise over time, and I never messed around with the fans.



    here's a video regarding the 2014 and 2015 which goes into throttling and fan behaviour. The 2015 iMac does run quite hot, but never seems to throttle.
     
  10. Merlin_the_mog thread starter macrumors newbie

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    Sep 24, 2016
    #10
    Here's my bench mark. I'm not sure why my minimum and maximum frames are lower than yours. That does seem a bit strange. I guess the overall score difference is about what I'd expect.
    Mine got up to 99C on the first run, on the second run, it rose until it touched 102 C, then the fans got a little louder (still just over 1500), and the temperature dropped and then hovered around 99-101 C.

    Screen Shot 2016-11-21 at 19.22.28.png
     
  11. IngerMan macrumors 6502a

    IngerMan

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    #11

    I did get lower min max numbers but the score stayed about the same. I just posted the best numbers ;)
     
  12. Merlin_the_mog thread starter macrumors newbie

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    Sep 24, 2016
    #12
    I did some more tests, and actually my fan goes up to 2000-2200 when running the benchmark. This seems to be what's keeping the temp around 100 C. It's very audible at these speeds.

    I'd really appreciate it if someone with the same spec (i7 4.0GHz, m395x) could give me some feedback on the temperatures and fan speeds they're seeing.
     
  13. vddobrev macrumors regular

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    Oct 28, 2016
    Location:
    Haskovo, Bulgaria
    #13
    I don't have the same specs, but for what it is worth, here is some feedback for the iMac from my signature, ran benchmark 3 times:

    Max fan speed on auto: 1600rpm
    Max GPU temperature: 96º

    Fan speed on manual: 2200rpm
    Max GPU temperature: 86º
     
  14. Merlin_the_mog thread starter macrumors newbie

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    Sep 24, 2016
    #14
    Thanks Vddobrev, that's helpful - what GPU does your iMac have? (it doesn't say in your signature)
     
  15. vddobrev macrumors regular

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    Oct 28, 2016
    Location:
    Haskovo, Bulgaria
    #15
    AMD Radeon R9 M395 2048 MB
     
  16. IngerMan macrumors 6502a

    IngerMan

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    Michigan
    #16
    Merlin,

    I hope someone tests this on the i7 M395X for you. I ran a few more tests on my i5 M395 and found the fans only get up to mid 1700's after 3 tries, ironically is seemed to get cooler on the 4th run. I found I could run this test in the background to view the temp and fans. Also ironically I started getting better scores, not sure if that was because it was in the background?

    Screen Shot 2016-11-22 at 8.11.38 AM.png Screen Shot 2016-11-22 at 7.59.48 AM.png
     
  17. Merlin_the_mog thread starter macrumors newbie

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    Sep 24, 2016
    #17
    Yes, I saw this video, and that's one of the reasons I was worried about my iMac. The temps and fan speeds I'm seeing seem quite a lot higher than what's described in this video though.
     
  18. cynics macrumors G4

    Joined:
    Jan 8, 2012
    #18
    What's the ambient temperature?

    I notice significant difference in CPU temp when encoding videos due to ambient. This time of year (I keep my house cool ~65-67f) I'll see 85-90c in the summer (house about 72-73f) I'll see 90-95c all at the idle fan speed. It seems strange to me the difference doesn't directly corespond with ambient but I don't know much about thermal dynamics and never cared to learn.

    I guess my point is GPU temp between systems can vary wildly without taking everything into account.
     
  19. sboychuck, Nov 27, 2016
    Last edited: Nov 27, 2016

    sboychuck macrumors regular

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    Sep 19, 2014
    Location:
    Thousand Oaks, CA
    #19
    Well, my temp made it to 86C, but I also have my fans turned up to about 2500 (they will go to a max of 2850) running SMC FanControl 2.6. Seems to be ok? Yes, the fans are a bit noisy, but my MAC's stay cool. When doing intensive work, I generally turn up the fans to a tolerable level. By the way, the temp in the house is 72F right now. This is a late 2015 27-inch running Sierra. Thanks...
     

    Attached Files:

  20. CWallace macrumors 603

    CWallace

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    Aug 17, 2007
    Location:
    Seattle, WA
    #20
    I run Diablo 3 a fair bit on my i7 / M395X and those temps are what I see. The GPU will throttle it's clockspeeds if it hits thermal limits. I don't notice much if any fan noise, however. Ambient temps are in the 60s. I keep my room pretty dust-free - are the intake grills on the bottom edge of the machine clogged? Might want to blow some compressed air in there and in the grill in the back and see if that helps.
     
  21. Merlin_the_mog thread starter macrumors newbie

    Joined:
    Sep 24, 2016
    #21
    I ended up returning my iMac for a replacement because I didn't feel comfortable with the temperatures and fan speeds I was seeing.
    I received the replacement today, and the good news is that this one is behaving much more nicely.
    I've just run the same benchmark three times, and the maximum temperature from the GPU die was 99C across the three runs with the fan speed maxing out around 1500. Most of the time the GPU was at 97C.
    With the previous iMac, fan speed would go up to 2000-2200 after a couple of runs and temperature would be 100-101, occasionally getting up to 103C.
    I know that's only a couple of degrees C, but the general fan noise and heat generation from this one while retaining those temperatures seems to be significantly lower. It also took much longer to reach the high temperatures in the first place.
     
  22. Merlin_the_mog thread starter macrumors newbie

    Joined:
    Sep 24, 2016
    #22
    I'm also seeing higher benchmark scores now (about 10% better), and the benchmarks are consistent now. Before the scores seemed to get worse the hotter my iMac got. Looks like my previous iMac was throttling, but this one is running at full speed all the time, so if anyone else sees anything like this, it's definitely worth doing something about it.
    Thanks to everyone who responded. Your information and assistance was much appreciated. :)
     

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