Heat Difference is Huge 6-core 15" 2018 vs 4-core 15" 2017. 160 degrees vs 126 degrees.

Discussion in 'MacBook Pro' started by Appledoesnotlisten, Nov 28, 2018.

  1. Appledoesnotlisten, Nov 28, 2018
    Last edited: Nov 28, 2018

    Appledoesnotlisten macrumors member

    Appledoesnotlisten

    Joined:
    Dec 2, 2017
    #1
    Hello,

    I just bought a refurbished 6-core 15" 2018 and it is running extremely hot (150-162 degrees).

    Indexing is done, the system has settled down, but the machine is much hotter than my 2017 sitting next to me. The GPUs are more or less the same. And, the 2017 is loaded with 40 tabs in safari + emails + powerpoint, while the 2018 is only running 5 simple safari tabs.

    When I connect 4K external monitors to each of them, the difference is even bigger. The numbers are below: 160 degrees vs 126 degrees.

    I am really upset.

    Do you think it's because
    (1) I bought a refurbished one or
    (2) because it's 6-core or
    (3) it's supposed to be like this?
     

    Attached Files:

  2. BigJohno macrumors 65816

    Joined:
    Jan 1, 2007
    Location:
    San Francisco
  3. deadworlds macrumors 65816

    deadworlds

    Joined:
    Jun 15, 2007
    Location:
    Citrus Heights,CA
    #3
    Running as expected. Seriously, people need to understand that CPUs run hot. Add more cores and it runs hotter. It is not uncommon to see some CPUs reach 90C (194F) and up. Your computer will shutdown on its own if heat is an issue.

    Use your computer and don’t worry about how hot the CPU gets unless it’s causing an issue.
     
  4. silver_mtb Suspended

    silver_mtb

    Joined:
    Nov 27, 2018
    #4
    I will say #2. Also because the laptop does not have enough of these...
    [​IMG]

    and Apple will not let you undervolt the CPU, which can help with heat.
     
  5. Appledoesnotlisten, Nov 28, 2018
    Last edited: Nov 28, 2018

    Appledoesnotlisten thread starter macrumors member

    Appledoesnotlisten

    Joined:
    Dec 2, 2017
    #5
    Yes, nothing suspicious there.

    P.S. I also own a freshly bought quad-core 13" 2018. Out of curiosity, I connected it to 2x4K monitors and it's now proudly driving the following:

    2 x (3840x2160) + 2560x2160 (itself) + Many apps at 118 degrees. Completely silent, just slightly warm. And my 15" is sitting next to it with no external monitors and only MacRumors open, with the same temperature.

    I wish the newest 15" could do what 13" does without melting my desk. Really wanted to keep the 2018 15", but maybe its because I bought refurbished. Perhaps someone had returned it as heating too much, Apple "geniuses" did not find anything wrong and put it up for sale again. That's my only explanation.
     
  6. loybond macrumors 6502

    Joined:
    Aug 1, 2010
    Location:
    The True North, Strong and Free
    #6
    No, not crazy. The max temp is 100 or 105 c for most Intel CPUs. Under load, laptops will go almost right up to the maximum and then start throttling.
     
  7. dof250 macrumors regular

    Joined:
    Jun 3, 2014
    #7
    I experienced exactly the same. The 15" runs way to hot with a 4k monitor connected. When running on internal graphics its ok, but I'm using it daily with the 4k monitor and that heats it up significantly.
    I have now bought the 13" quadcore 2018 which doesn't have de dGPU so I hope this will run much cooler. Its now done indexing so today will be the test day :)
     
  8. leman macrumors G3

    Joined:
    Oct 14, 2008
    #8
    Under load, yes. But definitely not in idle.
    --- Post Merged, Nov 29, 2018 ---
    Oh please. The MBP has excellent airflow for its form factor. And how are extra vents supposed to help anyway unless you run fans full speed all the time?
     
  9. buran-energia macrumors regular

    Joined:
    Oct 9, 2017
    #9
    I'd try a newer 15 model with Vega 20. It probably has a few tweaks when it comes to CPU cooling, not to mention a more powerful and probably cooler GPU.
     
  10. Appledoesnotlisten thread starter macrumors member

    Appledoesnotlisten

    Joined:
    Dec 2, 2017
    #10
    But my 15” 2017 runs significantly cooler than this 15” 2018. Both at idle and under load.The GPUs are almost identical, so it’s either 2 additional cores or something like thermopaste. Very upset.
     
  11. dof250 macrumors regular

    Joined:
    Jun 3, 2014
    #11
    Yeah I experienced the same when upgrading from the 2017 15" to the 2018. I think the additional cores are what's causing the increase...
     
  12. Ma2k5 macrumors 68020

    Ma2k5

    Joined:
    Dec 21, 2012
    Location:
    London
    #12
    The 8th Gen CPU's run far hotter than previous generations and I don't think any laptop manufacturer has changed their design to accommodate for it. A lot of users on the Window laptops are under-volting these to calm the thermals down and even improve performance during extended loads.

    Your use case is expected.
     
  13. Ploki macrumors 68040

    Joined:
    Jan 21, 2008
    #13
    2018 15" are hot. Like, *really* hot.

    I was amazed that using the same system and same usage ramped up fans on the 2018 15" i9, but the old 2012 i7 quad was quietly idling and chillin'.

    The fans are almost never idle.

    For me, it was hot enough that I returned mine and will get a Mac Mini instead.
     
  14. gnasher729 macrumors P6

    gnasher729

    Joined:
    Nov 25, 2005
    #14
    And 100 degree Celsius is 212 degree Fahrenheit.
     
  15. SoyCapitanSoyCapitan macrumors 601

    SoyCapitanSoyCapitan

    Joined:
    Jul 4, 2015
    Location:
    Paris
    #15
    Intel was promising 10nm chips by now so Apple and others didn’t feel the urgent need to redesign cases. Intel’s roadmap failed so we have chips that run too hot for slim and light laptops.

    The GPU adds heat too when powering the 4K display. An eGPU should help here but right now these things haven’t hit the Goldilocks zone. They are either too big, too ugly, the cheap ones don’t have enough features or and the features ones are too expensive. The closest to best balance is the Mantiz but they don’t offer warranty or nearby replacement because it ships from Taiwan.
     
  16. maflynn Moderator

    maflynn

    Staff Member

    Joined:
    May 3, 2009
    Location:
    Boston
    #16
    The 2018 MBP has two more cores and a higher end GPU in an enclosure that was not specifically designed for 6 cores. Seeing 70c while running a 4k monitor isn't really that hot in the scheme of things. I don't have a 4k monitor, but I do have the old apple Cinema Display and my current temps are 60c. When I'm on iGPU and the battery, I see 30 to 40c which is very cool imo.

    Remember when comparing the old MBP to the new model, we have 50% more cores in the 2018 model, and that just going to add to the heat
     
  17. Ploki macrumors 68040

    Joined:
    Jan 21, 2008
    #17
    well... then you either have to:
    1) redesign the chassis to accommodate hotter chips
    2) down-clock said chips and advertise them as such
    3) get better chips from somewhere else.

    I'm not buying a macbook pro from intel, i'm buying it from apple.

    There's always a contingency plan - apple had none.
     
  18. PBG4 Dude macrumors 68030

    PBG4 Dude

    Joined:
    Jul 6, 2007
    #18
    The new 6 core CPUs run much hotter and are able to pull more watts than the older 4 core CPUs.

    My 2017 2.9GHz CPU can run around 3.1GHz forever under full load, according to intel’s CPU application. Have run multiple 8-12 hour Blender sessions and have not been throttled below advertised performance.

    The 2018 MBPs have the same case and cooling setup, but is dealing with a much hotter chip that will pull far more than the advertised 45W if you let it. Also, there is a new membrane between the top case and keyboard that could slow heat dissipation through keyboard holes that wasn’t slowed in the 2017 models.
     
  19. Ploki macrumors 68040

    Joined:
    Jan 21, 2008
    #19
    I dont think the silicone membrane matters that much. The chips are just over-powered for such as small chassis.
     
  20. PBG4 Dude macrumors 68030

    PBG4 Dude

    Joined:
    Jul 6, 2007
    #20
    Yeah, I don’t know how much it would affect heat dissipation either, but it is a significant difference from the 2017 model, which is why I mentioned it.
     
  21. maflynn Moderator

    maflynn

    Staff Member

    Joined:
    May 3, 2009
    Location:
    Boston
    #21
    I think it does have an effect, but at best its minimal, though any help in cooling these laptops would be a good thing
     
  22. Appledoesnotlisten thread starter macrumors member

    Appledoesnotlisten

    Joined:
    Dec 2, 2017
    #22
    I want to enjoy the 2018 keyboard without the 2018 overheating. Performance of the 2017 machine is more than enough for me.

    Perhaps I can just convince Apple to put a 2018 keyboard into my 2017 (touchpad is faulty and the machine is under warranty, so top case replacement might be needed) and keep the 2017?
     
  23. SoyCapitanSoyCapitan macrumors 601

    SoyCapitanSoyCapitan

    Joined:
    Jul 4, 2015
    Location:
    Paris
    #23
    There wasn’t a viable contingency plan.

    It takes two years to design a chassis and change the supply chain.

    AMD don’t offer a competitive mobile CPU in this space. Lower single core performance, will still throttle, no TB3 support.

    Laptops had to be released as the same time as competitors. All competitors in thin and light also suffer from Intel’s heat.

    No company can underclock CPUs. They are obliged with Intel to ship at the specs listed on Intel’s spec sheets. Under clocking violates terms and just pisses off internet fanboys.
     
  24. Appledoesnotlisten thread starter macrumors member

    Appledoesnotlisten

    Joined:
    Dec 2, 2017
    #24
    So, in addition to suffering now because of the keyboard and heating issues, the resale value of these machines will plummet once this hardware nonsense get resolved.
     
  25. BigMcGuire Contributor

    BigMcGuire

    Joined:
    Jan 10, 2012
    Location:
    California
    #25
    I have a work issued Dell XPS with an 8th Gen i7 (i7-8750H) (6 cores) @ 2.20Ghz.
    My 2017 MBP 13' has a 7th Gen i5 (i5-7287U) (2 cores) @ 3.30Ghz.

    The heat difference between these two laptops when doing CPU intensive tasks is night and day. XPS constantly overheats, is difficult to use on lap, and has fans screaming all the time while my MBP is cool to the touch and rarely turns on the fans if ever.

    I've had the XPS overheat several times, shut off, run itself to 0% overnight, …. I am not impressed with it. :( The CPU I love.

    But yes, a MASSIVE heat difference in these new CPUS.

    That said… The i7-8750H is amazing and keeps up with my workflow like no other processor ever has while I develop in Visual Studio 2017. It powerhouses through processes noticeably faster than my last work computer: Dell Precision Tower 3620 (Intel(R) Core(TM) i7-6700 CPU @ 3.40GH). Minus the heat output, I like it. Can't imagine it in a MBP body though...
     

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