I can confirm, my monitor is an LG ultrawide 29'' (2560x1080) and the only setup that consumes about 4-6w is the 1080p (1920x1080) in clamshell mode, and it stays at 45-50ºC(113-122ºF). If I try anything else it goes up to 18W and the temps stay between 60 and 65ºC(140-150ºF). It really is a bummer
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(2019) 16" is HOT & NOISY with an external monitor! :(
- Thread starter Appledoesnotlisten
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There are obviously bigger problems with the thermal configuration of this Macbook. Some people ruined their Graphics Card with an external monitor setup:
https://discussions.apple.com/thread/250878229?page=6
https://discussions.apple.com/thread/250878229?page=6
Last edited:
In my case yes, when using an eGPU and the display directly connected to the eGPU, the internal dGPU pulls only ~4-5W and thus I don't have heat / power / noise issues anymore.
This wattage increase is a bit ridiculous... If only there was an option for us to use the iGPU to completely ignore the dGPU when connected to an external monitor...
What I have been doing is putting the fans at 100% then reduce to 60% after a while.
What I have been doing is putting the fans at 100% then reduce to 60% after a while.
This post is intended to shed some light on these 'issues' that people are reporting. These heat and fan threads are getting ridiculous to say the least. The MacBook can pull 100W of power from the wall. about 35-40 of that goes to the CPU, the memory and SSD use power, and you also need another 30 to power the dGPU (I don't think Apple really says anywhere what the real numbers are...), plus you have to power the screen, speakers, fans, keyboard backlight, USB devices, and other random things.
That heat has to go somewhere. Fans are needed to remove the heat from the computer. You're essentially putting a 100W space heater on your desk or lap if you're running it at full tilt!
Now, since the external displays are wired into the dGPU, the mere act of plugging in a monitor will turn the GPU usage on and use a few watts. And of course, if you do 3D graphics or fancy 2D compositing, or use the GPU for calculations in photo or video editing, you're going to simply increase that power.
At some point the fans are going to turn on. However, with this MacRumors page open in Safari, a VLC window playing a downloaded moving, and a Finder window open, my 2019 16" i7 is running cool (60 degrees C) and the fans are not audible. They may be spinning at some low RPM but you can't hear them. I don't know what speed they are at because I don't have any fan monitoring software installed (more on that later)
![Screen Shot 2019-12-24 at 11.17.02 AM.png]( "Screen Shot 2019-12-24 at 11.17.02 AM.png")
Here is the Intel Power Gadget that monitors your CPU temperature, utilization, and frequency. It also draws some nice graphs. I have labeled the temperature graph. You can see it go down as I unplug the monitor. Then I close the programs I had open (Activity Monitor and the Intel Gadget), and you can see how low the temperature goes. Almost down to 40 degrees. I plug the monitor back in (Acer 27" 2560x1440 connected with a USB-C to DisplayPort cable) and you can see the temp go back up slightly. Again, nothing running, this is just the mere act of plugging a monitor back in which activates the dGPU.
There are people here who say things like "I can hear my fans, all I have open is Firefox and 3 tabs, this computer is defective and I am returning it to Apple tomorrow." Then, they post a screen shot of some kind of temperature monitoring app, there's a hundred graphs and number, you can see in their menu bar that they have 6 other apps running...
Your machine is running hot because you are using the CPU. It's that simple.
Activity Monitor alone can take a decent chunk of CPU.
![Screen Shot 2019-12-24 at 11.14.54 AM.png]( "Screen Shot 2019-12-24 at 11.14.54 AM.png")
It says 13.5% for itself. But if you look at top, which is a command-line UNIX tool for seeing similar information, it shows Activity Monitor using almost double!
![Screen Shot 2019-12-24 at 11.14.27 AM.png]( "Screen Shot 2019-12-24 at 11.14.27 AM.png")
Which one should we believe? Anyway, what I am getting at is that you need to look at what's running and what's generating heat - AKA, using power. You might only have two tabs open in a browser, but those tabs might be running all kinds of Javascript that is showing ads, drawing graphics, collecting user data...so look and see how much CPU your browser is using. 5 tabs of one website might be equal to 1 tab of another website.
Also, turn off all those silly monitoring apps. You don't need to know the temperature of your Mac to the exact degree. If it's warm, it'll feel warm. The fans will automatically come on when the system needs to cool down. Apple isn't going to let these overheat. You're just going to give yourself OCD monitoring that stuff. Not to mention, most of those apps aren't efficient or they use the GPU to draw your shiny graphs and gauges! You're using 50% of your CPU with those apps and that's causing your computer to get hot! How stupid is that!
Remove your silly fan control apps while you are at it. Let the system do itself. Your car has fans that come on. So does your house. You don't have to play with them or monitor them. You're just going to wear your fans out keeping them on all the time, even though you think you're helping your system out. I have a 2017 MacBook Pro on my desk right now that is awaiting a replacement fan, the bearing is bad and it clicks/buzzes, that's way more annoying than any air blowing noise will ever be.
Also, those background apps in your menu bar can suck up CPU big time. Dropbox has been known to be a big CPU user. People always bring up Spotlight indexing but that happens very quickly on a new machine. It doesn't take 'days' like some people mention. It will run for a while when you add a ton of photos or files to your new Mac (like fill up the whole 1TB/2TB SSD), but for most people it's done in like a half hour of turning the machine on.
So before anyone starts complaining about their computer being warm or loud (which if you're using, it's going to be, that's just how it works), take a look in Activity Monitor at what the processes are that are using the most CPU and creating the biggest energy impact (you will have to turn that column on). You might be surprised at what you see. If your fans come on and your machine is hot but nothing is showing usage, or it's something like 'kernel task', then you have a problem and should go visit the Apple Store. If it's just Firefox, Chrome, Dropbox, or whatever else you have running, there is nothing wrong. Contact whoever makes that program if you think it's buggy and is using more CPU than you think it should.
![Screen Shot 2019-12-24 at 11.21.52 AM.png]( "Screen Shot 2019-12-24 at 11.21.52 AM.png")
In that image, you can see Activity Monitor is using more CPU than VLC does to play a full screen video on my 27" monitor! Ridiculous!
The 'yes' processes are simply running the command:
yes > /dev/null &
In a terminal window. The idea is that when you run these, it will start a 100% CPU usage process. Useful when you want to run your CPU hard to test the fans coming on or to see how hot it will get (it's useful to run more than one of these....1 per CPU core, 2 if you have HyperThreading). You can end them by entering:
killall yes
That heat has to go somewhere. Fans are needed to remove the heat from the computer. You're essentially putting a 100W space heater on your desk or lap if you're running it at full tilt!
Now, since the external displays are wired into the dGPU, the mere act of plugging in a monitor will turn the GPU usage on and use a few watts. And of course, if you do 3D graphics or fancy 2D compositing, or use the GPU for calculations in photo or video editing, you're going to simply increase that power.
At some point the fans are going to turn on. However, with this MacRumors page open in Safari, a VLC window playing a downloaded moving, and a Finder window open, my 2019 16" i7 is running cool (60 degrees C) and the fans are not audible. They may be spinning at some low RPM but you can't hear them. I don't know what speed they are at because I don't have any fan monitoring software installed (more on that later)
Here is the Intel Power Gadget that monitors your CPU temperature, utilization, and frequency. It also draws some nice graphs. I have labeled the temperature graph. You can see it go down as I unplug the monitor. Then I close the programs I had open (Activity Monitor and the Intel Gadget), and you can see how low the temperature goes. Almost down to 40 degrees. I plug the monitor back in (Acer 27" 2560x1440 connected with a USB-C to DisplayPort cable) and you can see the temp go back up slightly. Again, nothing running, this is just the mere act of plugging a monitor back in which activates the dGPU.
There are people here who say things like "I can hear my fans, all I have open is Firefox and 3 tabs, this computer is defective and I am returning it to Apple tomorrow." Then, they post a screen shot of some kind of temperature monitoring app, there's a hundred graphs and number, you can see in their menu bar that they have 6 other apps running...
Your machine is running hot because you are using the CPU. It's that simple.
Activity Monitor alone can take a decent chunk of CPU.
It says 13.5% for itself. But if you look at top, which is a command-line UNIX tool for seeing similar information, it shows Activity Monitor using almost double!
Which one should we believe? Anyway, what I am getting at is that you need to look at what's running and what's generating heat - AKA, using power. You might only have two tabs open in a browser, but those tabs might be running all kinds of Javascript that is showing ads, drawing graphics, collecting user data...so look and see how much CPU your browser is using. 5 tabs of one website might be equal to 1 tab of another website.
Also, turn off all those silly monitoring apps. You don't need to know the temperature of your Mac to the exact degree. If it's warm, it'll feel warm. The fans will automatically come on when the system needs to cool down. Apple isn't going to let these overheat. You're just going to give yourself OCD monitoring that stuff. Not to mention, most of those apps aren't efficient or they use the GPU to draw your shiny graphs and gauges! You're using 50% of your CPU with those apps and that's causing your computer to get hot! How stupid is that!
Remove your silly fan control apps while you are at it. Let the system do itself. Your car has fans that come on. So does your house. You don't have to play with them or monitor them. You're just going to wear your fans out keeping them on all the time, even though you think you're helping your system out. I have a 2017 MacBook Pro on my desk right now that is awaiting a replacement fan, the bearing is bad and it clicks/buzzes, that's way more annoying than any air blowing noise will ever be.
Also, those background apps in your menu bar can suck up CPU big time. Dropbox has been known to be a big CPU user. People always bring up Spotlight indexing but that happens very quickly on a new machine. It doesn't take 'days' like some people mention. It will run for a while when you add a ton of photos or files to your new Mac (like fill up the whole 1TB/2TB SSD), but for most people it's done in like a half hour of turning the machine on.
So before anyone starts complaining about their computer being warm or loud (which if you're using, it's going to be, that's just how it works), take a look in Activity Monitor at what the processes are that are using the most CPU and creating the biggest energy impact (you will have to turn that column on). You might be surprised at what you see. If your fans come on and your machine is hot but nothing is showing usage, or it's something like 'kernel task', then you have a problem and should go visit the Apple Store. If it's just Firefox, Chrome, Dropbox, or whatever else you have running, there is nothing wrong. Contact whoever makes that program if you think it's buggy and is using more CPU than you think it should.
In that image, you can see Activity Monitor is using more CPU than VLC does to play a full screen video on my 27" monitor! Ridiculous!
The 'yes' processes are simply running the command:
yes > /dev/null &
In a terminal window. The idea is that when you run these, it will start a 100% CPU usage process. Useful when you want to run your CPU hard to test the fans coming on or to see how hot it will get (it's useful to run more than one of these....1 per CPU core, 2 if you have HyperThreading). You can end them by entering:
killall yes
I prefer top to Activity Monitor because of the overhead. I set it to sample at 3 second intervals like so:
It's identical to the command I use on my FreeBSD/OpenBSD machines (no surprise!), and my old MBP running El Capitan. The default on Catalina is to sort by CPU so the -o flag is optional.
As a programmer and scientist, I appreciate the beauty and elegance of less. I like tiny apps which take minimal resources. On my Macs, I only have two apps running in the menu bar:
Fanny - Shows fan speed and cpu/gpu temp. Monitors only. Almost no overhead.
Clipy - Stores old clipboard selections. Extremely handy and tiny footprint.
One more on the MBP 16:
Pock - Again, a simple, tiny app which displays the Dock on the touch bar.
I also contribute to all three apps on github so I have a good idea how the code works. I know they are not using too many cycles.
I connect to various 4k TVs at work for presentations (prefer using my Mac to those horrible Dell laptops) and so far haven't noticed anything troubling with the thermals. However, it's never dead silent there so that might have masked fan noise if any.
Bash:
top -o cpu -s 3As a programmer and scientist, I appreciate the beauty and elegance of less. I like tiny apps which take minimal resources. On my Macs, I only have two apps running in the menu bar:
Fanny - Shows fan speed and cpu/gpu temp. Monitors only. Almost no overhead.
Clipy - Stores old clipboard selections. Extremely handy and tiny footprint.
One more on the MBP 16:
Pock - Again, a simple, tiny app which displays the Dock on the touch bar.
I also contribute to all three apps on github so I have a good idea how the code works. I know they are not using too many cycles.
I connect to various 4k TVs at work for presentations (prefer using my Mac to those horrible Dell laptops) and so far haven't noticed anything troubling with the thermals. However, it's never dead silent there so that might have masked fan noise if any.
There is no software fix for this. MacBook Pro’s have always been like this in the retina era. My 2013 was the same. Non pixel doubling retina means rendering at much higher resolution and downsampling. That combined with hardware wiring of dGPU for external displays means this is just how it works.
I'm not a programmer nor an engineer.. so I may ask a really "silly" question
Could this wiring of dGPU for external displays, change with a software patch? Is it strictly hardware issue?
I have two 4K monitors attached (LG UltraFine) and zero issues with lack of cooling or overheating.
Sorry, but while I understand graphs and monitoring ups the CPU processing a bit, I don't think that's the major issue here. I can look at my activity monitor with no external monitor plugged in, temperature graphs up, and the fans are not audible. I plug in my monitor, which is a smaller resolution than my MBP's own screen, and GPU usage goes to 20w, and the fans become very audible as the temperatures rise very quickly.
Compare that to another person in this thread, who is able to plug in their widescreen 3440x1440 screen, which a much higher pixel count than my own monitor, and their GPU wattage stays at 5w-6w. Also, if I switch to '1080p' on my own screen, it also stays down at 4w-5w. But that looks like crap.
Compare that to another person in this thread, who is able to plug in their widescreen 3440x1440 screen, which a much higher pixel count than my own monitor, and their GPU wattage stays at 5w-6w. Also, if I switch to '1080p' on my own screen, it also stays down at 4w-5w. But that looks like crap.
Reading that they had a single machine I think they likely just had a faulty one, it happens. I don't think they killed the GPU themselves with their testing but it just was faulty from the factory. Just my opinion though.
I noticed some people in here are saying a few things.
1. The laptop runs hotter with external monitor connected
2. The fans even at 2,400 RPM are audible and annoying
For me the laptop idles at 58c on the CPU and 60c on the GPU when connected to an external monitor with the lid of the laptop opened so the internal display is also being driven. The power consumption on the Radeon GPU at this time is about 18 Watts. With the lid closed this falls to below 8 watts.
My fans are spinning between 2,000 and 2,400 RPM with an external display connected and the laptops internal display active. I do not find this noisy at all, in-fact I cannot hear the laptop on my desk at these speeds, I don't believe my hearing is impaired.
So my take away would be, if you have noisy fans at 2,000-2,400 RPM perhaps the fans are faulty and you should have them replaced by Apple.
For me the computer has zero issues with noise when connected to an external display until I push it to a high CPU and/or GPU load which is to be expected and happens the same even without an external display connected.
I write this not to say there's no issue everyone should go home but to provide a data point that there are machines out there that don't have this issue so you may want to try exchanging your machine. I do believe many of you when you say the system is running hot and noisy with external displays and I don't think that is the behaviour you should expect from a working unit.
Out of curiosity how are you connecting the MBP to your monitor? I'm just wondering if going through a dock has anything to do with it (seems unlikely but who knows). I'm just using a USB-C to DP connector direct to the monitor.
Its not hardware problem it is a problem with the drivers, it can be fixed with future updates, and it is not because someone have a faulty macbook, the only resolutions that draw 5-6w are the native 4k and 1080p, and it must be in clamshell mode I think. Any other res will make the mac draw 18-20w iddle
This isn't just about the native resolution of the monitor - it is the effective resolution you run it at. For instance, someone running a 4K 27" monitor is unlikely to run it at native 4K resolution - if they did it would require little processing power but everything would look tiny. They are more likely to run it at something that looks like 2560x1440. The crucial part here is that MacOS can run this in either 'scaled mode' or 'low resolution mode'
The former renders at twice the 2560 resolution then downscales it to the 4K panel to give the best possible 'retina like' picture. This is quite a lot of work. The latter simply throws out that resolution and lets the monitor's scaling do its stuff which is usually crap and blocky. In fact I haven't seen these low resolution options recently so they might have even been removed in later MacOS versions.
The person running a 3440x1440 screen - that is not actually all that high a resolution, it is simply a normal resolution but ultra-wide. That means no special scaling is required and it can simply be run at its native resolution - i.e. low processing overhead.
I’m running parallels and my temperature sits at 45c without a display connected.
HOWEVER as soon as I connect a display regardless of the specs it goes onto the 55c - 60c pushing 18w or more due to the dGPU being pushed.
Again, why can’t I use the iGPU for 1080p monitors and use the dGPU when connected to 4K?
So I ask why drive the dGPU so high that makes the temps rise between 55-60c?
I think it comes down to these new GPU's using 7nm. The transistors are packed much denser than the older 16nm GPU's most of us had in prior macs. This has also been a thing on Ryzen 3 which also uses 7nm. The voltages have gone down but not by a huge amount so you're dealing with a lot more transistors per physical area, harder to cool that.
As for the iGPU on external display thing, that's just how Apple has decided to do it since 2012 with the Retina machines. I think they likely made this decision due to the iGPU being very weak and people would notice stuttering even in 2D loads.
I mean personally I even notice how weak the iGPU is even on the internal display. Just scrolling web pages it's very choppy compared to the 5500m. Was the same on my 2015" model which had iGPU + M370X GPU.
That is 100% normal operation. Also, because the way the dGPU is wired you have to use it for external monitors, you don't have a choice.
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That's more of Reddit's fault than anything.
These temperatures with external monitor are the same I see on my 2018 560X. I am by no means happy with those values, since I get around 34 without external monitor. The decision to force dGPU with whatever monitor I plug does not get thumbs up from me. I want to type on my machine doing light work without any heat on my hands. I can get it on 13 inch but I don't want such a small screen.
Apple is giving us the choice of no choice on this one. I was expecting a different approach on these new 16 inch machines.
People talk a lot about how Intel is dropping the ball on 10nm, but my 14nm processor ramps up from 34 to 50 just by attaching an external display. It is not the processor, it is the GPU that elevates the whole heat pipe!!! If Apple chooses to call PRO because it has a dedicated GPU, give us users who don't want this "issue" a 15 Air or something (but with proper cooling, not the Air joke).
It is working as intended? Yes. Is it satisfactory for me? No. And for the looks of some users, it does not get for them also. I am sorry, I would like to part some cash for the new 16, when I saw the news of better thermals I was trilled, but they chose to give it to performance instead of letting users choose if they want comfort or performance.
I see some users mentioning clamshell mode. I don't see Touch Bar functionality on a stand alone keyboard, I want to still use the keyboard that comes with the machine. To be forced to use it that way to get the desired comfort from a 3000EUR machine because of a "design decision", no thanks. Stop blaming Intel for something that Apple should have solved since the first dual GPU MacBook Pro in 2011...