15" Retina MBP: CPU t under full load

Discussion in 'MacBook Pro' started by maratus, Nov 21, 2012.

  1. maratus macrumors 6502a

    maratus

    Joined:
    Jun 12, 2009
    Location:
    Canada
    #1
    Dear macrumors members and guests!

    I'm starting this thread mainly to obtain some nice statistics on 15" Macbook Pro with Retina Display, which may help others to decide on a purchase or determine if their machine's cooling system is working within specs. Many of us uses their machines for computation-heavy tasks and knowing that cooling system is capable is very important for system stability and reliability. If the CPU runs at 105C, it'll start to throttle down to stay at that temperature, since it is TJMax for almost all Intel CPU nowadays. It will not only hit the performance, but running at such high temperatures will also reduce your computer lifetime and increase the chance of failure.


    The idea is to run 8 threads from terminal that will put 100% load to all 8 virtual cores (4x real cores + hyper threading) with fans at their highest RPM. Then you need to measure CPU core temperature and enclosure/battery temperature after 8-10 min and post the results.

    Here's the protocol:
    1. Install iStat Menus (http://bjango.com/mac/istatmenus/)
    It's free for 15 days and is actually the best monitoring program I know.
    2 (optional). Set all fans to the highest RPM. Go to Sensors -> Edit Rules and create a new one. After that you can select it from menubar icon!
    It's not required as both fans will fish all the way to 5500rpm once you 100% load the CPU.

    3. Open terminal and execute this command:
    yes > /dev/null
    create a new terminal window and repeat 8 times. Now you have 8 processes that load your CPU up to 800%.

    [​IMG]


    Here's what iStat menubar looks like on the 2.6Ghz model:
    [​IMG]


    I had my hands on three different RMBP machines, and here're the results:


    1st:
    2.6Ghz, 16Gb RAM (July 2012):

    CPU: 105C
    Battery / Enclosure: 30C / 29C

    2nd:
    2.3Ghz, 8Gb RAM (September 2012):

    CPU: 83C
    Battery/Enclosure: 30C / 30C

    3rd:
    2.6Ghz, 16Gb RAM (November 2012):

    CPU: 103C
    Battery/Enclosure: 30C / 30C



    All measurements are takes after at least 10min with fans at full rpm.
    P.S. The 1st and the 3rd are done with both stock and replaced thermal compound. 2nd (2.3Ghz model) was completely stock.
     
  2. b0fh666 macrumors 6502a

    b0fh666

    Joined:
    Oct 12, 2012
    Location:
    south
    #2
    I see no mention of room temperature in the 'methodology', not considering that makes all this testing useless :D

    cheers
     
  3. maratus thread starter macrumors 6502a

    maratus

    Joined:
    Jun 12, 2009
    Location:
    Canada
    #3
    I agree, but there's no direct "room" temperature here since not everyone has a thermometer ready to hand.

    However, both battery and enclosure sensors aren't very sensitive to the heat from the radiator so they could be used as a reference.

    Ideally, one need to provide Air intake t. Nevertheless, battery/enclosure t is good enough for normalising the results in unusually hot/cold environments.
     
  4. maratus thread starter macrumors 6502a

    maratus

    Joined:
    Jun 12, 2009
    Location:
    Canada
    #4
    Even though we don't have precise air temperature readings ;) it seems that the difference between 2.3Ghz and 2.6Ghz is enormous. I can confirm that in both 2.6Ghz machines I tested it was the same stepping (Stepping 9 (09h))
    according to MacCPUID.

    It is still to be confirmed whether there're any different steppings available around (for 2.6 model in particular). It's also unknown if 2.3Ghz is so much cooler of it's me who is unlucky!

    Considering 2.7Ghz model, if there're any users of the Ultimate configuration here, I'd really appreciate some feedback!
     
  5. Sound Evolution macrumors 6502

    Joined:
    Oct 30, 2007
    Location:
    Netherlands
    #5
    Hi, I have the 2.7Ghz. model and have thermal issues, in the sense I feel the laptop get WAY to hot.

    I am willing to help and do the test. However me being a noob... :D After you put all cores to work as described above, How you stop the process?
     
  6. Blondie :) macrumors 6502a

    Blondie :)

    Joined:
    May 12, 2010
    Location:
    Prescott, AZ
    #6
    The only way that room temp actually makes a difference is by decreasing the amount of convection from the laptop to the surroundings. Unless you're talking about a massive room temp difference, the temp difference won't actually mean much.
     
  7. b0fh666 macrumors 6502a

    b0fh666

    Joined:
    Oct 12, 2012
    Location:
    south
    #7
    really?

    In my experience it can get scalding hot if the ambient is hot (and boy, it DOES get hot here in the tropics), but when it is cool you barely notice heat buildup. same type of workload, of course.

    the 'ambient air' measurement is currently saying 40 celsius, but that has to be inside the laptop as it is ˜22.

    cheers
     
  8. Blondie :) macrumors 6502a

    Blondie :)

    Joined:
    May 12, 2010
    Location:
    Prescott, AZ
    #8
    The reason that you don't notice the buildup as much when it's cold is due to conduction. When the bottom cover of the macbook is cooler, heat transfer from the CPU to the outside will be more efficient. But, as more heat transfers through the case, the case heats up anyways. As I mentioned before, the larger source of heat transfer will come from convection (outside air running over the bottom cover of your macbook). That's why people have been investing in fans like this one: http://www.moshimonde.com/product/zefyr-2.aspx
     
  9. maratus thread starter macrumors 6502a

    maratus

    Joined:
    Jun 12, 2009
    Location:
    Canada
    #9
    That's fine, if your ambient t is 40C them you'll have corresponding enclosure/battery temperature increase which will cancel this variable.

    Hi, you can just close all windows one by one, or quit (cmd + Q) the Terminal.app

    However, make sure you do the test for at least 10 min to let the temperature stabilise. Please note if your room is abnormally hot or cold, even though it will be translated into higher enclosure/battery temperature.

    If you need help with iStat Menus settings, you can PM me.
     
  10. maratus thread starter macrumors 6502a

    maratus

    Joined:
    Jun 12, 2009
    Location:
    Canada
    #10
    So I will probably get a fresh 2.3GHz model to double check that difference. Surprisingly, I see a lot of threads and discussions about heat but yet no one is bothered to do a test so that we can have at least general view on this problem. C'mon people, do some tests and post the results! Everyone will benefit out of this!
     
  11. mactoday macrumors member

    Joined:
    Dec 13, 2006
    Location:
    Moscow, Russia
    #11
    Fans speed should be on the maximum if you loaded CPU up to 800%, maximum fans speed 6500rpm, your MacBook Pro has tons of dust inside, clean it up.
     
  12. maratus thread starter macrumors 6502a

    maratus

    Joined:
    Jun 12, 2009
    Location:
    Canada
    #12
    No, it's not. Those fans inside of RMBP max out at 5500/6000rpm respectively. They're different from those in cMBP
     
  13. maratus thread starter macrumors 6502a

    maratus

    Joined:
    Jun 12, 2009
    Location:
    Canada
    #13
    So if no one is interested, why are there so many "my mbp runs hot" threads?
     
  14. maratus thread starter macrumors 6502a

    maratus

    Joined:
    Jun 12, 2009
    Location:
    Canada
    #14
    So maybe there's at least one knowledgeable person on this forum who can confirm my statistics? Anyone?
     
  15. Ploki macrumors 68000

    Joined:
    Jan 21, 2008
    #15
    I did CPU test http://www.coolbook.se/CPUTest.html and it does get smoking hot. 2.7ghz model.

    103 degrees before fans start ramping

    settles on 101 degrees when fans ramp up.

    funny GPU die also heats up significantly when doing this test.

    it doesnt seem any hotter than my old mbp, cooler even, and more quiet.
     
  16. maratus thread starter macrumors 6502a

    maratus

    Joined:
    Jun 12, 2009
    Location:
    Canada
    #16
    Yeah, that 2.7Ghz is a heat machine indeed....
     
  17. JronMasteR macrumors 6502

    JronMasteR

    Joined:
    May 4, 2011
    Location:
    Switzerland
    #17
    Exactly the same here. Ultimate Model, 100-103°C after 5 minutes. This CPU really gets very hot. Already thought that this was a bad machine, but it seems normal.

    Edit: Forgot to say, mine is with stock thermal compound.
     
  18. Schranke macrumors 6502

    Schranke

    Joined:
    Apr 3, 2010
    Location:
    Copenhagen, Denmark
    #18
    What settings did you use for testing.
    Have a 2.7GHz model myself and would like to throw in data as well
     
  19. w00t951 macrumors 68000

    w00t951

    Joined:
    Jan 6, 2009
    Location:
    Pittsburgh, PA
    #19
    1) Unusual, because Intel chips usually throttle themselves around 98C.
    2) The GPU can be explained by two factors: First, the heat sink for the CPU and GPU is connected - which defies logic. They're probably sharing some heat. Second, some tasks can be offloaded onto the GPU by OS X to take advantage of a video processor's superior parallel processing capacities.
     
  20. Ploki macrumors 68000

    Joined:
    Jan 21, 2008
    #20
    Big test, 1 repetitions, 8 instances.
    enough to get it hot and for fans to ramp up.


    Makes sense. If CPU gets smoking hot before fans kick in the whole cooling system is already at 70 degrees, and depending where the sensor is some heat gets to the GPU sensor.
     
  21. Schranke macrumors 6502

    Schranke

    Joined:
    Apr 3, 2010
    Location:
    Copenhagen, Denmark
    #21
    Just made the test with
    Did the test after a restart and reseting of the SMC
    Had intel power gadget running to see power usage and CPU frequency.

    Started from idle:
    Here are the numbers i got out of it:
    The room is about 20°C.

    (did a 2nd run 5 min after the first just to see how it went, the peaks are from that run.)
     
  22. Ploki macrumors 68000

    Joined:
    Jan 21, 2008
    #22
    what do you use to see CPU clock?
     
  23. Schranke macrumors 6502

    Schranke

    Joined:
    Apr 3, 2010
    Location:
    Copenhagen, Denmark
    #23
  24. Ploki macrumors 68000

    Joined:
    Jan 21, 2008
  25. Schranke macrumors 6502

    Schranke

    Joined:
    Apr 3, 2010
    Location:
    Copenhagen, Denmark
    #25
    np, it is great for seeing what is in use, found a problem with notification center and Facebook.
    Could not understand some of the spikes i got so i kept an eye on activity monitor and console.
     

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