(2019) 16" is HOT & NOISY with an external monitor! :(

[Appledoesnotlisten]

OP wrote:
"Macs native is: 3072x1920. Did you mean 3072x1920? If not, why would I set my display at 1920x1080?"

Because that's how the display will work best when attached to the MBP.

You don't want "the same resolution as the MacBook".
You want the best one for the display.
They will not be the same.

You have a 24" 4k display.
The MBP will run best using two possible settings:
- FULL 4k mode, pixel-for-pixel (text will be too small)
or
- HiDPI mode (looks like 1080p) -- text will be normally-sized.

If you try to run the display at ANY OTHER resolution, you're going to start "scaling", which will tax the MBP's GPU heavily.
Sounds like that's what you're doing now.
And that's why the MBP is overheating.

Thanks for the input, just to clarify:

1) Both the 15” and the 16” run fine with ANY resolution, up to 3840x2400, as long as there is no external monitor. The problems arises when I connect an external monitor.
2) I am not mirroring the displays, the content is different on them.

So are the following settings supposed to work fine, if we disregard the fact that the text is too small? I am not able to pick the same refresh rate though.

 

[pshifrin]

My 2019 15 2.4/32/1tb/560x connected to the LG 24inch 4K (the model sold by Apple) is super quiet unless I do something like a quick transcode. Display running at default and laptop at 1440x900

 

[astrorider]

The screenshot is attached.

Btw,
1) It's colder in my room now,
2) I have decreased resolutions of both displays, and
3) No heavy apps open, but...

the results are still bad - the case is too warm and the fans are noisy: RPM1=3700 and RPM2=4000.
And remember, these fans are bigger, so they generate more noise at the same RPM.

P.S. If I limit fans at RPM1=RPM2, which is acceptable, the temperature quickly rises to 90+.

Your Windowserver is using a lot of GPU (81%). On the Mac I'm on, connected to a 5k display, WindowServer's GPU is less than 1%. I think WindowServer may be responsible for menu items. Have you tried quitting all those menu items with the graphs/statistics and seeing if it uses less GPU by checking with Activity Monitor only? Maybe those menu items are just poor at managing the GPU.

 

[Appledoesnotlisten]

Your Windowserver is using a lot of GPU (81%). On the Mac I'm on, connected to a 5k display, WindowServer's GPU is less than 1%. I think WindowServer may be responsible for menu items. Have you tried quitting all those menu items with the graphs/statistics and seeing if it uses less GPU by checking with Activity Monitor only? Maybe those menu items are just poor at managing the GPU.

WindowServer jumps to ~81% GPU very rarely, it's usually 0, but it keeps consuming 15-40% CPU no matter what. I have not figured out what WindowServer does yet.

Btw, I found several similar threads and people suggest that certain cables might run cooler, take a read:

“If your displays run on ThunderBolt or DisplayPort family interfaces, they will run cooler. (Conversely, if you changed to HDMI your Mac could be even hotter, as HDMI still contains the "heartbeat" refresh required by CRT displays. Sending more data generates more heat.)”

Macbook pro 15 2018 2 external 4k monitors - Apple Community

discussions.apple.com

Q: 2018 MBP overheating using external mo… - Apple Community

discussions.apple.com

 

[Appledoesnotlisten]

So, native for the 16" is 3072x1920 and my LG is in 2560x1440.

I've bumped the LG up to 3840x2160 and the laptop is still behaving, will leave it like this for a bit.

What are the highest resolutions for both displays that your computer can output while staying cool and silent?
I want to see if your LG is a better fit for the 16" than my Dell.

 

[Ries]

WindowServer jumps to ~81% GPU very rarely, it's usually 0, but it keeps consuming 15-40% CPU no matter what. I have not figured out what WindowServer does yet.

Btw, I found several similar threads and people suggest that certain cables might run cooler, take a read:

“If your displays run on ThunderBolt or DisplayPort family interfaces, they will run cooler. (Conversely, if you changed to HDMI your Mac could be even hotter, as HDMI still contains the "heartbeat" refresh required by CRT displays. Sending more data generates more heat.)”

Macbook pro 15 2018 2 external 4k monitors - Apple Community

discussions.apple.com

Q: 2018 MBP overheating using external mo… - Apple Community

discussions.apple.com

WindowServer is responsible for rendering the UI. Most likely one of those app's you're running in the top bar is causing a lot of unnecessary rendering and the GPU/CPU to spin up.

 

[gugy]

Weird this is happening to external monitors. Apple promotes up to two XDR displays can be supported. If a 4k display is having issues, I can't imagine when you hook up two 6k displays.

 

[CM_1986]

My 16" MBP actually began screaming violently and burst into flames when I plugged into my external today.

 

[Appledoesnotlisten]

My 16" MBP actually began screaming violently and burst into flames when I plugged into my external today.

What display and cable?
I am going to Apple Store tonight and will connect my macbook to THEIR XDR displays using THEIR cables. If it works, we will know that not all external monitors and cables are compatible.

 

[TimothyB]

Brought home my new 16" today and just tested it out on my external monitor. Here's just some very unscientific initial impressions with

Setup:
38" LG 38uc99-w (Native Resolution = 3840x1600)
MacBook Pro 16 (2.4Ghz, 32GB, 2TB, 5500m 8GB)
Monitor Connection = USB-C Thunderbolt Cable, 3 foot.
External Display setting = "More Space" for native resolution
Internal Display setting = "Default for Display"

Test 1:

1. Plugging in single thunderbolt cable from monitor to MacBook. Mac shows it is charging, currently at 78% (monitor capable of sending 60 watts)
2. While just setting the display to more space and installing creative cloud, area above keyboard because hot.
3. Worried about unneeded heat, I turned the monitor off and let Adobe install 11-12 programs while I walk away for an hour.

Test 2:

1. After an hour, I come back and wake the screen. Battery is now at 100%, about 6 Adobe apps are installed, top area of keyboard is cool.
2. I change some settings, test Illustrator, make sure Adobe is still downloading and installing. Top still remains cool.
3. I power the monitor on, after 5 minutes of doing nothing intensive, the area above keyboard is hot again.

So yes, just based off this, the computer will instantly run hotter.

1. I wonder, will it still run hot in clamshell mode with internal monitor, keyboard and mouse, not using the main display, so essentially back to 1 display?
2. Reminds me of my PC, where if I connect 2 displays to a Nvidia 2080, it will no longer throttle to a low frequency for daily use, but remain at a higher clock at all times.

EDIT: Update:

Test 3:

1. MacBook in clamshell mode connected to the external display
2. Left a YouTube background music video playing for a bout 15 minutes
3. Opened the lid to check the surface temp above the keyboard. Only slightly warm, or what I would say, normal.
4. So at least for docked, where you don't plan to use the MacBook display, an external will still work

Question is now, what happens if run in clamshell with 2 external monitors?

PS: I like how I can access the style commands for this post in the Touch Bar that I would have to scroll up on the screen to see.

 

[ascender]

What are the highest resolutions for both displays that your computer can output while staying cool and silent?
I want to see if your LG is a better fit for the 16" than my Dell.

I can have a look when I'm back tomorrow and let you know.

 

[Appledoesnotlisten]

Brought home my new 16" today and just tested it out on my external monitor. Here's just some very unscientific initial impressions with

Setup:
38" LG 38uc99-w (Native Resolution = 3840x1600)
MacBook Pro 16 (2.4Ghz, 32GB, 2TB, 5500m 8GB)
Monitor Connection = USB-C Thunderbolt Cable, 3 foot.
External Display setting = "More Space" for native resolution
Internal Display setting = "Default for Display"

Test 1:

1. Plugging in single thunderbolt cable from monitor to MacBook. Mac shows it is charging, currently at 78% (monitor capable of sending 60 watts)
2. While just setting the display to more space and installing creative cloud, area above keyboard because hot.
3. Worried about unneeded heat, I turned the monitor off and let Adobe install 11-12 programs while I walk away for an hour.

Test 2:

1. After an hour, I come back and wake the screen. Battery is now at 100%, about 6 Adobe apps are installed, top area of keyboard is cool.
2. I change some settings, test Illustrator, make sure Adobe is still downloading and installing. Top still remains cool.
3. I power the monitor on, after 5 minutes of doing nothing intensive, the area above keyboard is hot again.

So yes, just based off this, the computer will instantly run hotter.

1. I wonder, will it still run hot in clamshell mode with internal monitor, keyboard and mouse, not using the main display, so essentially back to 1 display?
2. Reminds me of my PC, where if I connect 2 displays to a Nvidia 2080, it will no longer throttle to a low frequency for daily use, but remain at a higher clock at all times.

EDIT: Update:

Test 3:

1. MacBook in clamshell mode connected to the external display
2. Left a YouTube background music video playing for a bout 15 minutes
3. Opened the lid to check the surface temp above the keyboard. Only slightly warm, or what I would say, normal.
4. So at least for docked, where you don't plan to use the MacBook display, an external will still work

Question is now, what happens if run in clamshell with 2 external monitors?

PS: I like how I can access the style commands for this post in the Touch Bar that I would have to scroll up on the screen to see.

Have you updated Catalina to 10.15.1? If not, try updating and repeating the test!

 

[wesStyle]

Brought home my new 16" today and just tested it out on my external monitor. Here's just some very unscientific initial impressions with

Setup:
38" LG 38uc99-w (Native Resolution = 3840x1600)
MacBook Pro 16 (2.4Ghz, 32GB, 2TB, 5500m 8GB)
Monitor Connection = USB-C Thunderbolt Cable, 3 foot.
External Display setting = "More Space" for native resolution
Internal Display setting = "Default for Display"

Test 1:

1. Plugging in single thunderbolt cable from monitor to MacBook. Mac shows it is charging, currently at 78% (monitor capable of sending 60 watts)
2. While just setting the display to more space and installing creative cloud, area above keyboard because hot.
3. Worried about unneeded heat, I turned the monitor off and let Adobe install 11-12 programs while I walk away for an hour.

Test 2:

1. After an hour, I come back and wake the screen. Battery is now at 100%, about 6 Adobe apps are installed, top area of keyboard is cool.
2. I change some settings, test Illustrator, make sure Adobe is still downloading and installing. Top still remains cool.
3. I power the monitor on, after 5 minutes of doing nothing intensive, the area above keyboard is hot again.

So yes, just based off this, the computer will instantly run hotter.

1. I wonder, will it still run hot in clamshell mode with internal monitor, keyboard and mouse, not using the main display, so essentially back to 1 display?
2. Reminds me of my PC, where if I connect 2 displays to a Nvidia 2080, it will no longer throttle to a low frequency for daily use, but remain at a higher clock at all times.

EDIT: Update:

Test 3:

1. MacBook in clamshell mode connected to the external display
2. Left a YouTube background music video playing for a bout 15 minutes
3. Opened the lid to check the surface temp above the keyboard. Only slightly warm, or what I would say, normal.
4. So at least for docked, where you don't plan to use the MacBook display, an external will still work

Question is now, what happens if run in clamshell with 2 external monitors?

PS: I like how I can access the style commands for this post in the Touch Bar that I would have to scroll up on the screen to see.

You can install istat menus (free trial) and see all the tempretures, cpu/gpu usage and most importantly how many watts gpu is draining and its core/memory frequencies.

If you can do the idle comparison between different modes (no ext display, with ext display, with ext display + clamshell) it will be much appreciated as no one did this yet.

On 2018 15" with no ext display and igpu I am at 40 C.
When I connect ext display rx560 drains 23W of power, temps are about 55-60C.
When I connect ext display but close the lid, rx560 drains 18W and temps are about 50C, sometimes a bit lower.
Fans are at ~2000rpm.

My display is samsung cj791 3440x1440 connected by thunderbolt 3 with 90W pd.
Also if I increase the resolution of the internal screen to the maximum available things become noticeably worse.

So, in the end, I mostly work with the lid closed and the thermals/fan noise are mostly okay. I wonder whether the new cooling + gpu in 16" is behaving any different.

 

[TimothyB]

You can install istat menus (free trial) and see all the tempretures, cpu/gpu usage and most importantly how many watts gpu is draining and its core/memory frequencies.

If you can do the idle comparison between different modes (no ext display, with ext display, with ext display + clamshell) it will be much appreciated as no one did this yet.

I’ll also check if the OS is updated too.

On 2018 15" with no ext display and igpu I am at 40 C.
When I connect ext display rx560 drains 23W of power, temps are about 55-60C.
When I connect ext display but close the lid, rx560 drains 18W and temps are about 50C, sometimes a bit lower.
Fans are at ~2000rpm.

My display is samsung cj791 3440x1440 connected by thunderbolt 3 with 90W pd.
Also if I increase the resolution of the internal screen to the maximum available things become noticeably worse.

So, in the end, I mostly work with the lid closed and the thermals/fan noise are mostly okay. I wonder whether the new cooling + gpu in 16" is behaving any different.

I will see what I can do with istat after my commute home from work Tuesday. So probably near the end of the day.

 

[chrono1081]

.

 

[callea]

Use it in clamshell mode. Less heat and no noise.

 

[maflynn]

Use it in clamshell mode. Less heat and no noise.

How is it less heat? My experience has been that heat is trapped between the keyboard and display and it actually runs hotter.

 

[callea]

How is it less heat? My experience has been that heat is trapped between the keyboard and display and it actually runs hotter.

I tested with istat menu. Less heat in clamshell mode.
Only one display instead of two, so minor load for gpu and cpu.

 

[wesStyle]

How is it less heat? My experience has been that heat is trapped between the keyboard and display and it actually runs hotter.

With the lid closed the gpu doesn't need to run a second high-resolution/hidpi screen which results in lower power consumption and thus about 6-10C lower idle temperatures (see my post above). The cooling system isn't affected by the closed lid.

 

[Apple2GS]

Did you test the machine before you installed any 3rd party software? Might be a bug in your monitoring apps that causes the machine to heat up and fans to ramp up.

 

[maflynn]

With the lid closed the gpu doesn't need to run a second high-resolution/hidpi screen which results in lower power consumption and thus about 6-10C lower idle temperatures (see my post above). The cooling system isn't affected by the closed lid.

Oh I understand what its doing but as I said, the heat is trapped. I had run my MBP in clamshell mode, but I saw it running hotter then with the lid open.

 

[ascender]

I've put the LG monitor up to 3840 x 2160 and have been doing some photo work in it for the last hour - I think there might be the slightest hint of fans blowing - but I'm struggling to tell if its the laptop or just background noise, even with my head almost against the laptop.

@Appledoesnotlisten

 

[btraill]

I've too noticed cooler temps (and less fan ramping) whilst in clamshell mode. I thought the heat would be trapped too but that doesn't seem to be the case.

 

[impulse462]

I've too noticed cooler temps (and less fan ramping) whilst in clamshell mode. I thought the heat would be trapped too but that doesn't seem to be the case.

It’s because the GPU only has to push one screen. I use my laptop in clamshell mode 90% of the time and that’s the case. Curious as to how the 16” will perform actually.

 

[triumph71]

I've been running 2 x 5k ultrafine displays since I jumped from my 2008 mp to a the 2016 mbp (4-core). It worked pretty hard to power both of those with the dGPU. When I upgraded to the 2018 (6-core) mbp, I also picked up a BlackMagic eGPU (RX580), and use that to power my primary display now, and that offloaded 'some' of the strain on the laptop itself. For the most part, this combo has been quiet, if not cool. The area around the TB3 ports and touchbar gets very warm, but the CPU utilization remains very low until I push it (multiple video streams, etc).

I'm hoping with the better thermal architecture and the more powerful 7nm dGPU, things should be even better for the late 2019 model.