New MBP 15" 2015(MJLT2LL/A) is overheating?

Discussion in 'MacBook Pro' started by UltraLEL, Sep 19, 2016.

  1. UltraLEL, Sep 19, 2016
    Last edited: Sep 19, 2016

    UltraLEL macrumors newbie

    Sep 19, 2016
    Hello guys.
    I have bought brand new MBP 15"(2015 MJLT2LL/A) and for some reason,i have installed iStat application to see what is going on my machine(temperatures of CPU/GPU and other things).
    So the main problem that when i'm booting my rNEW MBP,i'm gettin 50C of CPU(notice : all programms are turned off and CPU Is 98% on IDLE).
    So then,if ill go to browser and open some website,temperatures of CPU grows up to 60C-70C(how that is possible!?!?) and for these temperatures Coolers still don't want to raise RPM. (CPU is 90%-88% is IDLE )
    Also,i have tested with (opened one stream) and was little bit shocked, temperatures are grows up 80C-85C(and now Coolers starts to work properly,but with huge NOISE(like an engine of JET) and anyway,still 85%-90% CPU is IDLE )

    That machine was bought for programming and i'm very afraid,what will be happen when i will run many applications simultaneously.( it will burn my 2.5k$+? )

    So now i need some advices from you guys,i mean :
    1) Should i write to apple support and explain them what is going on?
    2) Is this OKAY for new rMBP,that have price 2.5k$ < ?!
    3) I need to reset SMC ?(is that fine for brand new macbook with warranty)
    4) Maybe i need to configure manually coolers to avoid that overheating problem ?

    PS Once i have worked with rMBP 13"(2013 year) and it was pretty amazing. No overheating,no noise fan,all is worked well.

    PPS Sorry for my english skills.
  2. ayeying macrumors 601


    Dec 5, 2007
    Yay Area, CA
    All normal.

    Laptop CPUs run in the upper 80s, 90s even hit over 100C no problem.

    If the fans are working. The system is doing its job. If the system shuts down, then the cooling isn't working properly and the computer is shutting down to protect itself.
  3. !!! macrumors 6502

    Aug 5, 2013
    My rMBP can get up to 100C just fine. What's not normal is 98% idle. Have you checked what's actually using the CPU via activity monitor?
  4. jerryk macrumors 601

    Nov 3, 2011
    SF Bay Area
    I bet when you look at activity monitor something is using the CPU.

    They scenario with the fans cycling up is just what the system is supposed to do when it gets warm. And if running the fans faster does not work, the system will throttle back the CPU so it produces less heat. All normal. As the system was designed to work.
  5. Queen6 macrumors 604


    Dec 11, 2008
    Flying over the rainforest at dawn - Priceless
    Welcome to Apple`s idea of cooling for the 15" MBP, quiet and cool as long as you don't push the system. Strictly speaking it`s not overheating to the point of damage, however it will run far hotter than`s PC counterparts and will throttle down as required.

    Sounds like your new to the 15" this is the price for being thin, nothing more, nothing less. Avoid flash, avoid Crome. Wait until you try it with an external display, the temperature you can ignore, the noise not so much. Consumer electronics running at such elevated temperatures has a cost. The quad core CPU & dGPU are driving forces for the high temperatures, if you need to work the OS X environment there are few if any options, if not there are many more...

  6. jerryk macrumors 601

    Nov 3, 2011
    SF Bay Area
    Interesting you mention an external display. I usually have my 2015 rMBP 15 (512, dGPU) attached to a couple of external displays and do not notice much fan noise. The only time I have fan noise is when I am doing something strenuous like compiling, encoding videos, or doing anything is Flash :mad:(yuck!!).
  7. Queen6, Sep 19, 2016
    Last edited: Sep 20, 2016

    Queen6 macrumors 604


    Dec 11, 2008
    Flying over the rainforest at dawn - Priceless
    Obviously much depends on the SW in use as by default with externals the dGPU is engaged. A lot of other factors come into play raised or flat on the desk, resolution of the externals. From my experience the 15" has always struggled with it`s thermals under load, equally your milage may vary.

    15" rMBP is not a bad machine by any means, equally it`s not best suited to heavy loads, unless portability is key with the dGPU being the weak point. In many respects is a complex subject with many variables.

  8. Samuelsan2001 macrumors 604

    Oct 24, 2013
    That sounds like a machine with issues take it back to Apple and get them to fix or replace. If you bought it brand new from Apple you can take it back for replacement for any or no reason at all within the first 14 days.
  9. UltraLEL thread starter macrumors newbie

    Sep 19, 2016

    Didn't check activity monitor,but via iStat app i saw that graphs of CPU.
    Anyway,when i'm booting rMBP temperatures start go grow up to 50C.

    yeah,seem you're right.

    Yes,i'm new for rMBP 15" and previsouly i have worked on rMPB 13".
    So via google and my impression,i'm doing conclusion that there is an difference between 15" and 13",because 15" is more hotter.
    Yesterday i have installed Parallels and it worked properly(i got 92C in high load of CPU, then it drops to 60C-50C).
    I think all is fine,just need to accept that concept of cooling from apple :) .
    Thanks for your advice.

    Yes,its fully brand new and 14 days are gone. I have bought an brand new machine and didn't use approx 1.5 months ,so anyway rMBP is under apple warranty and i think all is fine.

    Thanks for your comments!
  10. Queen6 macrumors 604


    Dec 11, 2008
    Flying over the rainforest at dawn - Priceless
    Being an owner & user of the 15" MacBook Pro forever; Over the years the 15" has frequently struggled with it`s thermals, especially when an external display is connected as the dGPU switches on by default, internal temperatures soar, equally there are some steps that can be taken to reduce the systems temperature;
    • Elevate the rear, aluminium passive coolers generally work best (I use RainDesign`s mStand & iLap)
    • Increase base fan RPM to 3K or as much as you are comfortable with (MacsFanControl or SMC Fan Control)
    • Limit the dGPU`s usage with gfxCardStatus
    • Swap out Chrome for Chrome Canary as it`s way more optimised for OS X and will extend battery run time, reduce thermals, Safari is generally best.
    • Swap out VLC for Movist as again it`s a reduced load on CPU/GPU
    • Uninstall or block Flash
    • Install an AD blocker Wipr or AdGuard works well
    • Powered coolers are very much a "mixed bag" when it comes to Mac portables, you need one that has a high capacity (100 CFM minimum) and preferably a large single fan, this can help to keep the 15" internal fans below 4K which for many is good enough as often it`s this point and beyond where the fans become intrusive. Don't expect a powered cooler impact internal temperatures, beyond a couple of degrees
    • Older notebooks can benefit from cleaning of the cooling system
    • Retina`s can benefit from cleaning of the cooling system, as the heat syncs are far smaller and loose efficiency faster, due to build up of dust
    • Replacing the thermal paste has been hit & miss, some with very positive results, some with no improvement over stock. Personally I would only do this on a Mac Portable that was either very old, or one that I can confirm was definitely running hotter than stock.
    • If your MBP has a discrete GPU, it will fire up when an external display is connected as default, temperatures will rise rapidly.
    • Consider a specific vertical stand when using a MPB in "Clamshell" mode allowing for greater circulation of air. Some recommend inverting the MBP in the stand with the exhaust at the top & intake at the bottom (Retina`s)
    The key to a quiet life with a 15" MacBook Pro is several incremental changes that do add up to reduce thermals. From my experience over the years if your going to push a 15" hard the fans are going to max out fast, with associated noise. If your using it with a moderate load life can be made quieter :) For the most part your MBP runs hot as that`s how Apple designed it, the trade off for form over, function, "thin & light"...

    The old adage still applies; it`s easier to keep a system cool, than cool-down an already overly hot machine. This being said it`s not strictly necessary, equally it`s nice to know that there are some options for reducing temperature out there.


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9 September 19, 2016