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

I found a solution to the fan running with an external monitor (2019 16" MBP, LG 4K).

I use an app called Lunar to turn off my Mac screen when I plug in the monitor. https://lunar.fyi/ It turns the screen fully off (in 'blackout mode'), not by just turning down the brightness. For me, that's enough to keep the fan off.

It has the same effect as putting the Mac in 'clamshell' mode (which I've heard also solves the fan problem), except this way you can still use the laptop's keyboard, trackpad, Touch Bar and speakers instead of having to buy externals.

It's expensive (20 euros), but there's a free trial to see if it works for you. For me, it was such a relief not having the fan on all the time.
 
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Use the LG Ultrafine, Apple Studio Display or Pro XDR.

If the external display is not a native resolution, the Mac has to work extra hard and you loose performance + more heat.
 
After two or three long years of being tortured by noise and heat, before the MacBook Pro 2019 with 5500M was about to go out of warranty (bought AppleCare+), I think I found a solution that allows it to reduce noise and heat with maximum performance without compromising. My external monitor is LG 27GN950 with DP connected to MBP.

Quickly modify the resolution or refresh rate of the external display and the built-in display through BetterDisplay.
(BetterDisplay is a great application on Mac, I highly recommend people with higher customization requirements for the display to buy the pro version, the author updates it very frequently and the features are very useful, but for modifying the resolution and refresh rate, the free version is enough.) Of course, it is also feasible in the mac OS system settings, but it may be very cumbersome because of high-frequency adjustment settings.

It is recommended to set the refresh rate of both to the same until it is observed that the power consumption of AMD's GPU is no longer approaching 20W (Fixed GPU power consumption in the status bar via istat menu to view and adjust parameters such as resolution and refresh rate in real time), at which time the fan also gradually reduces its speed to below 2000rpm to achieve a perfect silent effect.

For me, simply set the built-in monitor and external monitor at the same time to 60hz, 10bit color depth, you can avoid the GPU power consumption for a long time approaching 20w (transient power increase and decrease and will not affect the temperature and fan speed too much) may be different for each person's external monitor and need to figure out the items that need to be adjusted.

The above has left me with a MBP 2019 i9 5500M that is very close to the noise and heat of an Apple silicon MacBook on an external display, leaving me with a ton of money left over to avoid buying a new Mac because Apple/intel/AMD didn't do what they should have done (I hate notch).

Hope it helps.
 
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HOLAPX said:
For me, simply set the built-in monitor and external monitor at the same time to 60hz, 10bit color depth, you can avoid the GPU power consumption for a long time approaching 20w (transient power increase and decrease and will not affect the temperature and fan speed too much) may be different for each person's external monitor and need to figure out the items that need to be adjusted.
Click to expand...

Interesting, I'll give that a go. I notice the LG is a 4K display. What scaling settings are you using? I've read that it helps to use the same scaling on the internal display and the external monitor? Do you use the native 2x scaling on both displays or is it okay to have different scaling on each?
 
patthedog said:
Interesting, I'll give that a go. I notice the LG is a 4K display. What scaling settings are you using? I've read that it helps to use the same scaling on the internal display and the external monitor? Do you use the native 2x scaling on both displays or is it okay to have different scaling on each?
Click to expand...
The scaling setting I use on my LG 27GN950 4k monitor is 1920*1080, the native scaling used on the built-in screen.

I think the above is for reference only, because after my attempts, the same scaling is not guaranteed to work, on more different specs of monitors as well, because we don't know the technical details of AMD 5500M, so based on different monitors or connections, I think it might be hard to give a simple and accurate answer.

So while adjusting the display parameters (scaling settings/color depth/refresh rate, etc.) while checking the external monitor power consumption should be the easiest and most effective way. For example, when I set the built-in screen to 59.94Hz and the external to 60hz, the noise will be loud, but it's quiet when both at 60hz.
 
idasein said:
I found a solution to the fan running with an external monitor (2019 16" MBP, LG 4K).

I use an app called Lunar to turn off my Mac screen when I plug in the monitor. https://lunar.fyi/ It turns the screen fully off (in 'blackout mode'), not by just turning down the brightness. For me, that's enough to keep the fan off.

It has the same effect as putting the Mac in 'clamshell' mode (which I've heard also solves the fan problem), except this way you can still use the laptop's keyboard, trackpad, Touch Bar and speakers instead of having to buy externals.

It's expensive (20 euros), but there's a free trial to see if it works for you. For me, it was such a relief not having the fan on all the time.
Click to expand...

This worked for me too.

I got a Samsung 32" B702 4K monitor with USB-C. With the laptop closed, it gets hot pretty quick, and with the laptop open and the screen on the GPU has a mega power draw, but with the monitor open and screen turned off via Lunar it works great with an avg 6-7W GPU power draw, normal temps and fan speeds.

Not sure if this setup will work with multiple displays, but by the time I'm ready to add an additional display I'll probably also be ready to upgrade to apple silicon.
 
TRY the monitor with the HDMI port. Not the best, but may curb heat. I eventually had to do that with my 2013 15" MBP. They all had that issue.
 
I purchased a A2141 model in December 2019 with the following hardware:
  • 8-core i9 9880H
  • 32 GB RAM
  • Radeon 5500M
  • 1 TB SSD
My laptop is connected via HDMI and the Apple A2119 Adapter to a ViewSonic XG2705-2K monitor.
I've ugraded from Monterey to the latest Ventura 13.3.1 (a) yesterday.

Below I report the Radeon High Side reading in various settings.

Clamshell mode, Low Power disabled, 2560x1440, 60hz: ~4.7W idle and jumps to 9W under load.

Clamshell mode, Low Power disabled, 2560x1440, 120hz: ~5.7W idle and jumps to 10W under load.

Lid open, Low Power disabled, 2560x1440, 60hz: ~5W idle and jumps to 20W under load.

Lid open, Low Power disabled, 2560x1440, 120hz: 19W idle and jumps to 22W under load.

Lid open, Low Power enabled, 2560x1440, 60hz: ~5W idle and jumps to 13W under load.

Lid open, Low Power enabled, 2560x1440, 120hz: stays at 19W.


Laptop runs perfectly fine at 120hz in clamshell mode. When the lid is open, I have to enable Low Power mode and set the refresh rate to 60hz.
 
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I worked all day yesterday in Sonoma on my work M1 Pro and played Baldur’s Gate for several hours last night in Sonoma on my personal M1 Pro. So far so good.
 
On my 16" 2019 MacBook Pro connected to an external monitor, the overheating issue is still very much present in Sonoma. Back to Low Power Mode.
 
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Well, after a couple of days using Sonoma my recomendation is DON'T UPDATE.

There are problems to return from sleeping and the only solution is do a hard reset. Also, I notice a little bit more heat and now I hear the fans while when in older versions like Monterey and Ventura was completely silent and cold.

IF you don't update yet, don't do it now
 
JosepPont said:
Well, after a couple of days using Sonoma my recomendation is DON'T UPDATE.

There are problems to return from sleeping and the only solution is do a hard reset. Also, I notice a little bit more heat and now I hear the fans while when in older versions like Monterey and Ventura was completely silent and cold.

IF you don't update yet, don't do it now
Click to expand...
I’ve been doing full work days and playing Baldur’s Gate 3 on Sonoma. With zero issues.
 
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spiderman0616 said:
I’ve been doing full work days and playing Baldur’s Gate 3 on Sonoma. With zero issues.
Click to expand...
That's cool, however the issue we're discussing here is specific to Macbook Pro models with Intel CPUs. Those MacBooks experience a high wattage draw in their AMD GPU chips when using external displays. As far as I know, Apple Silicon chips don't have this problem or am I wrong?
 
JosepPont said:
Well, after a couple of days using Sonoma my recomendation is DON'T UPDATE.

There are problems to return from sleeping and the only solution is do a hard reset. Also, I notice a little bit more heat and now I hear the fans while when in older versions like Monterey and Ventura was completely silent and cold.

IF you don't update yet, don't do it now
Click to expand...
Thanks for sharing your experience. I will definitely wait a few months for a more stable release. I'm currently on Monterey, and I'm perfectly okay with it, but I'll be forced to update due to software compatibility.

Have you noticed a higher GPU wattage on Sonoma compared to previous versions? I mean, with the proper external display settings, you could run more external monitors with the lid open without needing to use low power mode in previous versions.

I use one 2k LG monitor and one FHD BenQ monitor. (Both at 60hz) When using the Mac with the lid open (so with three monitors in total), the GPU draws around 7 watts when idle, without needing of LPM turned on on Monterey.
 
I wish I skipped the hot & noisy 2019, kept using my 2011 MBP 13" 32nm and replaced it with a 2021 MBP 16" 5nm.

After a decade I'd upgrade that with a 2031 MBP 17" 0.7nm (A7).
 
I have no issues with i9 mb16 whatsoever.. maybe i do not care about occasional fan noise or a bit warmer body…
 
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