Putting the 16-inch MacBook Pro's thermal management to the test

Comments

• Reply 1 of 21

  melgross Posts: 33,510member

  November 20, 2019 9:14PM

  We also should remember that last year, the controversy began immediately, but was then mostly resolved when it was found that Apple had borked the OS by including pre production software, that when, in an update, was fixed, most of the throttling went away, and so did the controversy.

  
• Reply 2 of 21

  prismatics Posts: 164member

  November 20, 2019 9:28PM

  We should remember that the MacBook 15" had underwhelming GPUs mainly due to thermal constraints, where Apple really just cant put their hands off from designing themselves into a corner where they can't compete any longer; A win for everyone as Apple starts to regret their extortion-level flash pricing as well.
  
  Will be certainly interesting as AMD will launch Ryzen Mobile 4th gen very soon and AMD currently has a big lead on power consumption with their newest technology.
  I really hope they choose to move fully into mobile as well and make an 8-core SKU. I guess they chose their battle on server though as TSMC struggles to satisfy demand and those mobile chips have no other fab to be produced in since Samsung won't be there fast enough. Pairing AMD mobile with their Navi architecture (which has been shown to offer very good future outlooks) could mean even higher performance in the same power envelope.

  edited November 2019
• Reply 3 of 21

  dysamoria Posts: 3,430member

  November 20, 2019 9:44PM

  Is the benchmark utility running BOTH the CPU and the GPU at 100%?

  
• Reply 4 of 21

  cpsro Posts: 3,198member

  November 20, 2019 9:45PM

  The new thermal design has done nothing to avoid the throttling that occurs when memory larger than the L3 cache is beaten on in a random pattern, as opposed to sequentially the way common benchmarks access it. Multiple recent generations of Apple laptops do this and the latest model is no different. The CPU power consumed in such situations is a small fraction of the TDP, the CPU is driven well below the advertised sustained speed for all cores, and the processor temperature is only mildly warm.
• Reply 5 of 21

  nicholfd Posts: 824member

  November 21, 2019 12:14AM

  cpsro said:

  The new thermal design has done nothing to avoid the throttling that occurs when memory larger than the L3 cache is beaten on in a random pattern, as opposed to sequentially the way common benchmarks access it. Multiple recent generations of Apple laptops do this and the latest model is no different. The CPU power consumed in such situations is a small fraction of the TDP, the CPU is driven well below the advertised sustained speed for all cores, and the processor temperature is only mildly warm.

  I've seen you post almost this exact message 3-4 times in the past week.  Any links or proof for the new MacBook Pro 16"?

  
• Reply 6 of 21

  prismatics Posts: 164member

  November 21, 2019 1:30AM

  cpsro said:

  The new thermal design has done nothing to avoid the throttling that occurs when memory larger than the L3 cache is beaten on in a random pattern, as opposed to sequentially the way common benchmarks access it. Multiple recent generations of Apple laptops do this and the latest model is no different. The CPU power consumed in such situations is a small fraction of the TDP, the CPU is driven well below the advertised sustained speed for all cores, and the processor temperature is only mildly warm.

  What is this special kind of fake information? What do we have L1 I/D, L2, L3 caches, prefetch, TLBs and branch predictors for? Do you honestly believe that 2-way SMT as well as out of order execution and a very high cache hit rate (which by the way makes 4-way SMT unsuitable for consumer application) contribute to the CPU idling in a way where it is "mildly warm"?
  
  Sorry, random pattern memory access _never_ happens except if you have hash tables, Directed Acyclic Graphs or something but you are not using a CPU for that kind of problem, you are using GPUs or, if you have a very special application, Content Addressable Memory (or CAM for short, which is almost never used except for core network routers where you have some billion packets per second to be switched).

  edited November 2019
• Reply 7 of 21

  cpsro Posts: 3,198member

  November 21, 2019 2:08AM

  prismatics said:

  What is this special kind of fake information? What do we have L1 I/D, L2, L3 caches, prefetch, TLBs and branch predictors for? Do you honestly believe that 2-way SMT as well as out of order execution and a very high cache hit rate (which by the way makes 4-way SMT unsuitable for consumer application) contribute to the CPU idling in a way where it is "mildly warm"?
  
  Sorry, random pattern memory access _never_ happens except if you have hash tables, Directed Acyclic Graphs or something but you are not using a CPU for that kind of problem, you are using GPUs or, if you have a very special application, Content Addressable Memory (or CAM for short, which is almost never used except for core network routers where you have some billion packets per second to be switched).

  You can't see dark matter. Is it fake?
  You write random memory access _never_ happens and then proceed to describe instances where it can. (Congratulations!) People don't always use GPUs for the techniques you describe either.
  
  As stated previously, the throttling does not occur on a lowly Mac mini.
  
• Reply 8 of 21

  prismatics Posts: 164member

  November 21, 2019 2:22AM

  cpsro said:

  prismatics said:

  What is this special kind of fake information? What do we have L1 I/D, L2, L3 caches, prefetch, TLBs and branch predictors for? Do you honestly believe that 2-way SMT as well as out of order execution and a very high cache hit rate (which by the way makes 4-way SMT unsuitable for consumer application) contribute to the CPU idling in a way where it is "mildly warm"?
  
  Sorry, random pattern memory access _never_ happens except if you have hash tables, Directed Acyclic Graphs or something but you are not using a CPU for that kind of problem, you are using GPUs or, if you have a very special application, Content Addressable Memory (or CAM for short, which is almost never used except for core network routers where you have some billion packets per second to be switched).

  You can't see dark matter. Is it fake?
  You write random memory access _never_ happens and then proceed to describe instances where it can. (Congratulations!) People don't always use GPUs for the techniques you describe either.
  
  As stated previously, the throttling does not occur on a lowly Mac mini.
  

  This is not dark magic, you have performance counter registers for that.
  
  Please kindly educate yourself about the topic you write about.

  
• Reply 9 of 21

  anonconformist Posts: 199member

  November 21, 2019 12:08PM

  prismatics said:

  cpsro said:

  The new thermal design has done nothing to avoid the throttling that occurs when memory larger than the L3 cache is beaten on in a random pattern, as opposed to sequentially the way common benchmarks access it. Multiple recent generations of Apple laptops do this and the latest model is no different. The CPU power consumed in such situations is a small fraction of the TDP, the CPU is driven well below the advertised sustained speed for all cores, and the processor temperature is only mildly warm.

  What is this special kind of fake information? What do we have L1 I/D, L2, L3 caches, prefetch, TLBs and branch predictors for? Do you honestly believe that 2-way SMT as well as out of order execution and a very high cache hit rate (which by the way makes 4-way SMT unsuitable for consumer application) contribute to the CPU idling in a way where it is "mildly warm"?
  
  Sorry, random pattern memory access _never_ happens except if you have hash tables, Directed Acyclic Graphs or something but you are not using a CPU for that kind of problem, you are using GPUs or, if you have a very special application, Content Addressable Memory (or CAM for short, which is almost never used except for core network routers where you have some billion packets per second to be switched).
  
  
  

  HA!
  
  Besides having been a software developer for decades, for several years I've done developer support, and your claim about random memory access not happening except in the conditions you listed is a bunch of BS.  If for nothing else, Address Space Layout Randomization causes allocations to be... quite random by design, and this is done in allocating heaps and sub-allocations as well, and then you regularly have applications do lots of allocations interspersed with freeing memory, then doing more allocations, etc. causing fragmentation, and a lot of structures that have pointers linking to other things, that are followed when looking for things in memory.  Most applications don't only allocate and use data in linear arrays, but tend to use memory much more flexibly, even without using hash tables or DAGs.  Even a lot of software that is written with arrays as the abstraction isn't exactly linear in memory throughout the array due to underlying implementation, and linked lists are notorious for resulting in random memory access patterns (insofar as the pages accessed, which may remain the same for a given linked list for awhile are not allocated in sequential memory more often than not) even if a lot of the allocations started out with chunks of list elements being in short arrays to start with.
  
  Another big cause of random memory access patterns, even if you store your objects in fixed arrays happens with object-oriented data structures and code: unless you only ever put objects of a single class (not all sharing the same base class,  but precisely one class) those objects often have memory layouts that differ in size and layout, and often contain objects that also point to other objects, recursively, of many class types, so just the memory layout of the data alone (and quite often in the resulting object graph, it will NOT be a DAG) results in random memory access patterns while processing what appears to be a linear array of objects.  Once you have more than one particular type of class instance in an array, unless they're all sorted by type, you'll call virtual methods on the subclasses (or protocols/interfaces, depending on language) which means you're loading even more code into the CPU cache, worst-case scenario if the cache is very full and busy, on each object in the array being processed.  This is more common than your stated assumptions take into account: why do you think hyperthreading has so much hardware thrown at it? It's not just for program data, it's also for program code, to keep the CPU fed as much as possible, but short of all data being shared in nice linear layout in RAM, the CPU is evicting cache lines in LRU order (unless special instructions direct otherwise) and refilling them from random spots in RAM address space.  Mind you, that's just logical address space: that doesn't even address the fact that logical address space often results in one logical page being nowhere near another logical page when seen in the physical address space, and you really really don't want to consider what happens when your process calls into the OS and drivers, which they must do every so often, or your process isn't worth much in practice.
  
  While modern CPUs are waiting for main memory, even with hyperthreading, the core is left waiting a fair amount of the time, and the more cores you have, and the relatively less fast cache you have, the more that increases in severity: why do you think NUMA (Non-Unified Memory Architecture) machines exist? They exist because it's all too easy to saturate the memory bus and also die from CPU cache coherency overheads beyond a certain point.  When CPU cores are waiting on memory, the memory interface logic is using full power, but the core will be power-gated and down-clocked, so it isn't using max power.  If systems actually had main RAM that was fast enough, with no latency (and reading/writing main RAM on modern CPUs is done a whole cache line at a time, which is typically 32 bytes or more in some power of 2 in size) they'd scale linearly in performance with CPU clock speed, but that isn't what we have: we have CPUs that are extremely rarely running at peak efficiency, and that's almost always on artificial benchmarks, so those CPUs are being randomized in memory access most of the time, and are left running at lower core speeds/temperatures because they're twiddling their thumbs waiting for main memory.

  
• Reply 10 of 21

  melgross Posts: 33,510member

  November 21, 2019 3:16PM

  prismatics said:

  We should remember that the MacBook 15" had underwhelming GPUs mainly due to thermal constraints, where Apple really just cant put their hands off from designing themselves into a corner where they can't compete any longer; A win for everyone as Apple starts to regret their extortion-level flash pricing as well.
  
  Will be certainly interesting as AMD will launch Ryzen Mobile 4th gen very soon and AMD currently has a big lead on power consumption with their newest technology.
  I really hope they choose to move fully into mobile as well and make an 8-core SKU. I guess they chose their battle on server though as TSMC struggles to satisfy demand and those mobile chips have no other fab to be produced in since Samsung won't be there fast enough. Pairing AMD mobile with their Navi architecture (which has been shown to offer very good future outlooks) could mean even higher performance in the same power envelope.

  That’s not true. It went away when the OS was updated.
• Reply 11 of 21

  melgross Posts: 33,510member

  November 21, 2019 3:17PM

  
  

  cpsro said:

  The new thermal design has done nothing to avoid the throttling that occurs when memory larger than the L3 cache is beaten on in a random pattern, as opposed to sequentially the way common benchmarks access it. Multiple recent generations of Apple laptops do this and the latest model is no different. The CPU power consumed in such situations is a small fraction of the TDP, the CPU is driven well below the advertised sustained speed for all cores, and the processor temperature is only mildly warm.

  Most all thin laptops have a thermal problem, not just Apple’s.

  
• Reply 12 of 21

  alphadork Posts: 16member

  November 28, 2019 1:35AM

  You'd think new and improved thermal design would result in lower temperatures when performing similar operations. However, although I am using my shiny brand new 16" in exactly the same way that I was using my less-powerful early 2019 15.4", subjectively the 16" is hotter. Much much hotter.  On the one hand, great that it's successfully dissipating all that heat into my thighs, I suppose; but, on the other hand - why is there so much heat to dissipate?
• Reply 13 of 21

  Marvin Posts: 15,322moderator

  November 28, 2019 9:18PM

  alphadork said:

  You'd think new and improved thermal design would result in lower temperatures when performing similar operations. However, although I am using my shiny brand new 16" in exactly the same way that I was using my less-powerful early 2019 15.4", subjectively the 16" is hotter. Much much hotter.  On the one hand, great that it's successfully dissipating all that heat into my thighs, I suppose; but, on the other hand - why is there so much heat to dissipate?

  It says on the site:
  
  https://www.apple.com/macbook-pro-16/
  
  28% increase in airflow and they used the increased airflow to deliver 12 watts more maximum sustained power. More power = more heat and more airflow means more heat output.
  
  Every time Apple brings out a new laptop, people complain that its GPUs aren't as fast as they could be compared to PC gaming laptops that use close to desktop GPUs. Those do the same thing but to a more extreme level, they bump up the sustained power and increase the airflow so you get something that runs hot and in those cases sounds like a hairdryer.
  
  It's nice to have the extra power but sometimes it's better to have a cool laptop and just let processes take a bit longer. It would be good if Apple could add a mode to throttle processes (CPU and GPU) to allow the system to run cooler, just a slider in energy saver prefs like "run cooler ... run faster" and the cool option would try to keep the temperature close to idle temperature while running at maybe 50% maximum sustained power. There's a built-in unix command to do this and there's a script here:
  
  http://hints.macworld.com/article.php?story=20110131001708255
  
  If for example you want to run an encoding or rendering for a couple of hours and don't want to stress the machine and fans, that script will repeatedly sleep a given process for a short time so the CPU doesn't get too hot. There's another here:
  
  http://www.willnolan.com/cputhrottle/cputhrottle.html
  
  Ideally this kind of app/script would just run in the background and monitor the top user processes and throttle them to a specified limit rather than having to select them manually but it would probably have to use small time slices to avoid instability.
• Reply 14 of 21

  DuhSesame Posts: 1,278member

  December 21, 2019 9:38PM

  Marvin said:

  alphadork said:

  You'd think new and improved thermal design would result in lower temperatures when performing similar operations. However, although I am using my shiny brand new 16" in exactly the same way that I was using my less-powerful early 2019 15.4", subjectively the 16" is hotter. Much much hotter.  On the one hand, great that it's successfully dissipating all that heat into my thighs, I suppose; but, on the other hand - why is there so much heat to dissipate?

  It says on the site:
  
  https://www.apple.com/macbook-pro-16/
  
  28% increase in airflow and they used the increased airflow to deliver 12 watts more maximum sustained power. More power = more heat and more airflow means more heat output.
  
  Every time Apple brings out a new laptop, people complain that its GPUs aren't as fast as they could be compared to PC gaming laptops that use close to desktop GPUs. Those do the same thing but to a more extreme level, they bump up the sustained power and increase the airflow so you get something that runs hot and in those cases sounds like a hairdryer.
  
  It's nice to have the extra power but sometimes it's better to have a cool laptop and just let processes take a bit longer. It would be good if Apple could add a mode to throttle processes (CPU and GPU) to allow the system to run cooler, just a slider in energy saver prefs like "run cooler ... run faster" and the cool option would try to keep the temperature close to idle temperature while running at maybe 50% maximum sustained power. There's a built-in unix command to do this and there's a script here:
  
  http://hints.macworld.com/article.php?story=20110131001708255
  
  If for example you want to run an encoding or rendering for a couple of hours and don't want to stress the machine and fans, that script will repeatedly sleep a given process for a short time so the CPU doesn't get too hot. There's another here:
  
  http://www.willnolan.com/cputhrottle/cputhrottle.html
  
  Ideally this kind of app/script would just run in the background and monitor the top user processes and throttle them to a specified limit rather than having to select them manually but it would probably have to use small time slices to avoid instability.

  I've heard rumors that Apple had factory undervolted their 15-inch to compensate the heat.  I don't know if that's true or not, or Apple did the same on the 16".  Can you read the voltage from iStat Menus to see what's going on?  Thanks.
  
• Reply 15 of 21

  Marvin Posts: 15,322moderator

  December 22, 2019 10:58AM

  DuhSesame said:

  Marvin said:

  alphadork said:

  You'd think new and improved thermal design would result in lower temperatures when performing similar operations. However, although I am using my shiny brand new 16" in exactly the same way that I was using my less-powerful early 2019 15.4", subjectively the 16" is hotter. Much much hotter.  On the one hand, great that it's successfully dissipating all that heat into my thighs, I suppose; but, on the other hand - why is there so much heat to dissipate?

  It says on the site:
  
  https://www.apple.com/macbook-pro-16/
  
  28% increase in airflow and they used the increased airflow to deliver 12 watts more maximum sustained power. More power = more heat and more airflow means more heat output.
  
  Every time Apple brings out a new laptop, people complain that its GPUs aren't as fast as they could be compared to PC gaming laptops that use close to desktop GPUs. Those do the same thing but to a more extreme level, they bump up the sustained power and increase the airflow so you get something that runs hot and in those cases sounds like a hairdryer.
  
  It's nice to have the extra power but sometimes it's better to have a cool laptop and just let processes take a bit longer. It would be good if Apple could add a mode to throttle processes (CPU and GPU) to allow the system to run cooler, just a slider in energy saver prefs like "run cooler ... run faster" and the cool option would try to keep the temperature close to idle temperature while running at maybe 50% maximum sustained power. There's a built-in unix command to do this and there's a script here:
  
  http://hints.macworld.com/article.php?story=20110131001708255
  
  If for example you want to run an encoding or rendering for a couple of hours and don't want to stress the machine and fans, that script will repeatedly sleep a given process for a short time so the CPU doesn't get too hot. There's another here:
  
  http://www.willnolan.com/cputhrottle/cputhrottle.html
  
  Ideally this kind of app/script would just run in the background and monitor the top user processes and throttle them to a specified limit rather than having to select them manually but it would probably have to use small time slices to avoid instability.

  I've heard rumors that Apple had factory undervolted their 15-inch to compensate the heat.  I don't know if that's true or not, or Apple did the same on the 16".  Can you read the voltage from iStat Menus to see what's going on?  Thanks.
  

  There was a post saying the 15" throttling issue was from the voltage regulator having its limits set incorrectly:
  
  https://www.notebookcheck.net/Throttling-in-the-2018-Core-i9-Apple-MacBook-Pro-traced-to-improperly-set-VRM-power-limits.318176.0.html
  
  The 2019 model doesn't suffer from throttling so isn't suffering from the same issue. They seem to have just increased the power that the laptop can sustain, which would mean it produces more heat. It can handle that higher limit ok.
  
  The Volta app here was used to test the original throttling issue:
  
  https://volta.garymathews.com
  
  The undervolting feature there doesn't work on new models and shouldn't be used but it also has a power limit slider to cap the maximum power the system is allowed. This can be used to run the machine cooler. That would be a great option to have built into the system. Someone tested that on a 2018 model:
  
  https://forums.macrumors.com/threads/volta-with-mid-2018-mbp.2134756/
  
  Normally the power draw is around 45W (for CPU and GPU each) and Apple supplies an 85W/87W charger. The 2016 model has a 96W charger.
  
  If the macOS energy saver had that kind of maximum power draw option, a 16" Macbook Pro could perform like a Macbook Air on battery. This would make a huge difference for mobile software development because a lot of the time apps are indexing files in the background and using a lot of CPU unnecessarily. They could even do it a smart way so that burst power draw is higher than sustained so it mostly caps intensive processes. They can just put an icon in the menu bar showing that the system is being throttled.
  
  I made a Python script to do this on a per-app basis (attached) based on the one posted earlier. It can be run manually using "python script process_name max_CPU" or it can be setup as an easily run process using the bash profile:
  
  https://pastebin.com/7vStyc1S
  
  open terminal and type open ~/.bash_profile
  add the following line, changing the path to the script and save the file, then open a new terminal window:
  alias throttle='python /path/to/throttleCPU.py $1 $2'
  
  If a process like a render or video encoding is using a lot of CPU power, open a terminal window and type something like throttle handbrake 25 and it will look for that process and only allow it use 25% of the CPU. Hitting ctrl-c or closing the terminal window will let the process run at full speed. Processes take longer to finish when throttled but it means no fan noise when something is happening in the background.

  edited December 2019

  throttleCPU.py.zip 647B
• Reply 16 of 21

  DuhSesame Posts: 1,278member

  December 22, 2019 5:58PM

  Marvin said:

  DuhSesame said:

  Marvin said:

  alphadork said:

  You'd think new and improved thermal design would result in lower temperatures when performing similar operations. However, although I am using my shiny brand new 16" in exactly the same way that I was using my less-powerful early 2019 15.4", subjectively the 16" is hotter. Much much hotter.  On the one hand, great that it's successfully dissipating all that heat into my thighs, I suppose; but, on the other hand - why is there so much heat to dissipate?

  It says on the site:
  
  https://www.apple.com/macbook-pro-16/
  
  28% increase in airflow and they used the increased airflow to deliver 12 watts more maximum sustained power. More power = more heat and more airflow means more heat output.
  
  Every time Apple brings out a new laptop, people complain that its GPUs aren't as fast as they could be compared to PC gaming laptops that use close to desktop GPUs. Those do the same thing but to a more extreme level, they bump up the sustained power and increase the airflow so you get something that runs hot and in those cases sounds like a hairdryer.
  
  It's nice to have the extra power but sometimes it's better to have a cool laptop and just let processes take a bit longer. It would be good if Apple could add a mode to throttle processes (CPU and GPU) to allow the system to run cooler, just a slider in energy saver prefs like "run cooler ... run faster" and the cool option would try to keep the temperature close to idle temperature while running at maybe 50% maximum sustained power. There's a built-in unix command to do this and there's a script here:
  
  http://hints.macworld.com/article.php?story=20110131001708255
  
  If for example you want to run an encoding or rendering for a couple of hours and don't want to stress the machine and fans, that script will repeatedly sleep a given process for a short time so the CPU doesn't get too hot. There's another here:
  
  http://www.willnolan.com/cputhrottle/cputhrottle.html
  
  Ideally this kind of app/script would just run in the background and monitor the top user processes and throttle them to a specified limit rather than having to select them manually but it would probably have to use small time slices to avoid instability.

  I've heard rumors that Apple had factory undervolted their 15-inch to compensate the heat.  I don't know if that's true or not, or Apple did the same on the 16".  Can you read the voltage from iStat Menus to see what's going on?  Thanks.
  

  There was a post saying the 15" throttling issue was from the voltage regulator having its limits set incorrectly:
  
  https://www.notebookcheck.net/Throttling-in-the-2018-Core-i9-Apple-MacBook-Pro-traced-to-improperly-set-VRM-power-limits.318176.0.html
  
  The 2019 model doesn't suffer from throttling so isn't suffering from the same issue. They seem to have just increased the power that the laptop can sustain, which would mean it produces more heat. It can handle that higher limit ok.
  
  The Volta app here was used to test the original throttling issue:
  
  https://volta.garymathews.com
  
  The undervolting feature there doesn't work on new models and shouldn't be used but it also has a power limit slider to cap the maximum power the system is allowed. This can be used to run the machine cooler. That would be a great option to have built into the system. Someone tested that on a 2018 model:
  
  https://forums.macrumors.com/threads/volta-with-mid-2018-mbp.2134756/
  
  Normally the power draw is around 45W (for CPU and GPU each) and Apple supplies an 85W/87W charger. The 2016 model has a 96W charger.
  
  If the macOS energy saver had that kind of maximum power draw option, a 16" Macbook Pro could perform like a Macbook Air on battery. This would make a huge difference for mobile software development because a lot of the time apps are indexing files in the background and using a lot of CPU unnecessarily. They could even do it a smart way so that burst power draw is higher than sustained so it mostly caps intensive processes. They can just put an icon in the menu bar showing that the system is being throttled.
  
  I made a Python script to do this on a per-app basis (attached) based on the one posted earlier. It can be run manually using "python script process_name max_CPU" or it can be setup as an easily run process using the bash profile:
  
  https://pastebin.com/7vStyc1S
  
  open terminal and type open ~/.bash_profile
  add the following line, changing the path to the script and save the file, then open a new terminal window:
  alias throttle='python /path/to/throttleCPU.py $1 $2'
  
  If a process like a render or video encoding is using a lot of CPU power, open a terminal window and type something like throttle handbrake 25 and it will look for that process and only allow it use 25% of the CPU. Hitting ctrl-c or closing the terminal window will let the process run at full speed. Processes take longer to finish when throttled but it means no fan noise when something is happening in the background.

  Huh, I tried Volta a couple of days ago and it did not check my CPU voltage (Air 2019).  Though, why do you think someone said their 8-core is cooler than the 6-core?  If it's cooler, then it must be running in lower consumption, or perhaps because the silicon itself "isn't as dense" than their lower core-count siblings?  I've heard this theory before, where individual cores have more gaps between each other, making separate hotspots than a massive & big one.
  
  Then again, Boot Camp sucks a ton more power, it still does today.
  
  
  There are similar thing caught on my eyes about the Mac Pro, where a 12-core runs hotter than the 28-core one:
  
  28-core
  
  12-core
  
  
  Turns out they're not using the same die, the 12-core isn't a watered-down version of it.  Interestingly enough, the 12-core is running at ~160W where the 28-core hit ~200W.
  
• Reply 17 of 21

  DuhSesame Posts: 1,278member

  December 22, 2019 6:29PM

  Marvin said:

  DuhSesame said:

  Marvin said:

  alphadork said:

  You'd think new and improved thermal design would result in lower temperatures when performing similar operations. However, although I am using my shiny brand new 16" in exactly the same way that I was using my less-powerful early 2019 15.4", subjectively the 16" is hotter. Much much hotter.  On the one hand, great that it's successfully dissipating all that heat into my thighs, I suppose; but, on the other hand - why is there so much heat to dissipate?

  It says on the site:
  
  https://www.apple.com/macbook-pro-16/
  
  28% increase in airflow and they used the increased airflow to deliver 12 watts more maximum sustained power. More power = more heat and more airflow means more heat output.
  
  Every time Apple brings out a new laptop, people complain that its GPUs aren't as fast as they could be compared to PC gaming laptops that use close to desktop GPUs. Those do the same thing but to a more extreme level, they bump up the sustained power and increase the airflow so you get something that runs hot and in those cases sounds like a hairdryer.
  
  It's nice to have the extra power but sometimes it's better to have a cool laptop and just let processes take a bit longer. It would be good if Apple could add a mode to throttle processes (CPU and GPU) to allow the system to run cooler, just a slider in energy saver prefs like "run cooler ... run faster" and the cool option would try to keep the temperature close to idle temperature while running at maybe 50% maximum sustained power. There's a built-in unix command to do this and there's a script here:
  
  http://hints.macworld.com/article.php?story=20110131001708255
  
  If for example you want to run an encoding or rendering for a couple of hours and don't want to stress the machine and fans, that script will repeatedly sleep a given process for a short time so the CPU doesn't get too hot. There's another here:
  
  http://www.willnolan.com/cputhrottle/cputhrottle.html
  
  Ideally this kind of app/script would just run in the background and monitor the top user processes and throttle them to a specified limit rather than having to select them manually but it would probably have to use small time slices to avoid instability.

  I've heard rumors that Apple had factory undervolted their 15-inch to compensate the heat.  I don't know if that's true or not, or Apple did the same on the 16".  Can you read the voltage from iStat Menus to see what's going on?  Thanks.
  

  ......

  Also thanks for the Python 
• Reply 18 of 21

  hungcuong285 Posts: 1member

  December 23, 2019 3:29AM

  here is my new MacBook Pro 16 inch. It happened on YouTube's screen mode

  IMG_1429.jpeg 1.8M
• Reply 19 of 21

  Marvin Posts: 15,322moderator

  December 25, 2019 12:28AM

  hungcuong285 said:

  here is my new MacBook Pro 16 inch. It happened on YouTube's screen mode

  That looks like the same issue in the following video:
  
  
  
  In that video, it was caused by Flash. Someone in the comments on that video said they experienced it when their display color profile was set to sRGB. It could potentially be caused by automatic graphics switching.
  
  To remove old Flash plugins, they are in /Library/Internet Plug-Ins. Color profiles are in System Prefs > Displays > Color. Automatic Graphics Switching is in System Prefs > Energy Saver. You can also try rebuilding your driver caches by rebooting into safe mode holding shift at startup and then rebooting.
• Reply 20 of 21

  DuhSesame Posts: 1,278member

  December 28, 2019 5:08PM

  Marvin said:

  hungcuong285 said:

  here is my new MacBook Pro 16 inch. It happened on YouTube's screen mode

  That looks like the same issue in the following video:
  
  
  
  In that video, it was caused by Flash. Someone in the comments on that video said they experienced it when their display color profile was set to sRGB. It could potentially be caused by automatic graphics switching.
  
  To remove old Flash plugins, they are in /Library/Internet Plug-Ins. Color profiles are in System Prefs > Displays > Color. Automatic Graphics Switching is in System Prefs > Energy Saver. You can also try rebuilding your driver caches by rebooting into safe mode holding shift at startup and then rebooting.

  Speaking of displays,  I got people telling me that 16" has a screen that's less responsible than previous 15".  Some previous 15" owners said they've never noticed the ghosting before, I don't usually notice on my MacBook Air.  Panel's issue or just a firmware glitch?  I know there's the option for variable refresh rate.