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

[FF89]

Hi,

I would like to thanks everyone in this thread for the given inputs and I have managed to significantly reduced my 16" MBP 2019 (2.6 GHz 6-Core Intel Core i7, 32 GB Memory, 8GB AMD Radeon Pro 5500M) temperature and Radeon High Side power consumption for my usage in clamshell mode.

I am using my MBP in clamshell mode and connected to a 1440p monitor (Dell U2520D) with custom resolution setting on SwitchResX (V4.11, Full version) as follows:

Below is the results based on my personal experience. The data taken during idle and the Radeon High Side stays around 4.7 - 5 Watt. Even if I used my MBP like doing normal office work or watching youtube at 2160p resolution on safari, the Radeon High Side power will not go as high as 17 - 18 Watt (which is only happen when not using SwitchResX or when the lid is open). Running at much lower Radeon High Side power consumption also come with benefits:

• Low temperature of Radeon GPU Proximity and Radeon Memory Proximity, both around 43-45 degree Celsius under normal load.
• Due to the low GPU temperature, Left and Right fans only spinning around ~1840 and ~1700 rpm, respectively, which also contribute to less power consumption of MBP's operation under normal load.
• Due to the less power consumption from the Radeon and Fan, I can just use my Moshi displayport to usb-c cable to my macbook pro instead. The battery can last for 4-5 hours with external monitor under normal load, which is good for battery health rather than keep charging the battery all the time. And when I am using for extensive works like running parallels desktop to run windows 10 and its application, then only I connect the MBP to the external with USB-C for power delivery.

This is the results when I watch Youtubes videos at 2160p resolution on Safari.

​

Overall, I am satisfy with this results, but hopefully, there will be a solution for using external monitor with the MBP while the lid can be opened in the future on this thread.

Again, thanks everyone for sharing.

 

[ascender]

I've just got an i9 MacBook Pro as I need to be able to run some intel-only VMs. I've got it hooked-up to a 32" LG and its sitting at a nice, toasty 74 degrees with fans on low constantly....

This is nuts, unplug it from the monitor and immediately drops by 15 degrees or so, fans go off. I didn't have this problem previously with my last 16".

??

 

[MrGunny94]

I've just got an i9 MacBook Pro as I need to be able to run some intel-only VMs. I've got it hooked-up to a 32" LG and its sitting at a nice, toasty 74 degrees with fans on low constantly....

This is nuts, unplug it from the monitor and immediately drops by 15 degrees or so, fans go off. I didn't have this problem previously with my last 16".

??

Yea best option is to either go clamshell or just AirPlay.. which is what I have been doing for the time being

 

[koziolk]

Below is the results based on my personal experience. The data taken during idle and the Radeon High Side stays around 4.7 - 5 Watt. Even if I used my MBP like doing normal office work or watching youtube at 2160p resolution on safari, the Radeon High Side power will not go as high as 17 - 18 Watt (which is only happen when not using SwitchResX or when the lid is open)

Does it mean when the lid is open and you are using two screens - MBP one and an external - is still with 17 - 18 Watt? If so then SwitchResX helps almost nothing in this mode since my MBP with Dell U2520D without SwitchResX runs with 18-19 Watt.

 

[FF89]

Does it mean when the lid is open and you are using two screens - MBP one and an external - is still with 17 - 18 Watt? If so then SwitchResX helps almost nothing in this mode since my MBP with Dell U2520D without SwitchResX runs with 18-19 Watt.

Hello,

That’s true. So far, SwitchResX only help me during clamshell mode. Without the app, my MBP’s radeon High Side operates at 17-19 Watt during Idle, both in clamshell mode and open lid. Default setting with scan rate of 60Hz seems to be triggering the increase in power. Using custom resolution in SwitchResX seems to be helping reducing it.

If I try connect my MBP to an old TV with resolution of 1080p at 50 Hz (in clamshell mode), I dont need SwitchResX. It operates at 4.7-5 Watt. Once I open the lid with the TV connected, immediately the Radeon High Side jumps to 17-19 Watt at idle.

As I concluded above, I am satisfy because at the very least, SwitchResX still help me for low power operation and temperature of my MBP operation in clamshell mode. Better than nothing, I guess. And hoping that somebody here will find a way so that open lid operation achiveable in the future.

 

[koziolk]

That’s true. So far, SwitchResX only help me during clamshell mode. Without the app, my MBP’s radeon High Side operates at 17-19 Watt during Idle, both in clamshell mode and open lid. Default setting with scan rate of 60Hz seems to be triggering the increase in power. Using custom resolution in SwitchResX seems to be helping reducing it.

Makes sense. Have you tried to connect your MBP to an external UCB-C monitor (mine supports only HDMI/DP)? I've heard that it may help reduce Radeon's power consumption but haven't tried it yet.

 

[FF89]

Makes sense. Have you tried to connect your MBP to an external UCB-C monitor (mine supports only HDMI/DP)? I've heard that it may help reduce Radeon's power consumption but haven't tried it yet.

I did attempted since my Dell U2520D, which has the USB-C with Power delivery, DP, and HDMI ports. Before installing SwitchResX, I can confirm that connecting with either USB-C to USB-C, Moshi DP to USB-C, or UGreen HDMI to USB-C cables to the MBP in clamshell or open lid operation at default resolution (1440p) did not make any difference to the radeon high side power. All cases showed 17-19 Watt. I also tested with other resolution (1080p or 720p) in either clamshell mode or open lid operation for all different type of connections, again it did not help either.

Previously elsewhere, someone suggested to buy the expensive moshi DP to USB-C cable to improve it. I bought and tried, it still is showing 17-19 Watt either clamshell mode or open lid operation. This is a total waste of money.

As you can see from the picture i had posted, there are three cables:
1) White - Moshi DP to USB-C cable: Used only when I want to discharge the MBP's Battery while using the monitor,
2) Black - USB-C to USB-C cable that comes with Dell U2520D: Used most of the time when connecting my MBP, and
3) Black - UGreen mini USB to USB 2.0 cable to connect to the Dell U2520D for powering the Cooler Master Notepal A200 (This will not effect the testing, especially when connect the external monitor to MBP via DP or HDMI since they do not transfer data. The above tests were also tried before purchasing this cooler pad).

It seems that the suggestion of USB-C to USB-C cable did not help for this 1440p external monitor.

However, using custom resolution of SwitchResX helps the situation in clamshell mode. Any kind of connection either USB-C to USB-C, DP to USB-C, or HDMI to USB-C cables to the MBP, as long as I enable "use simplified setting", GTF, and scan rate of 59.950 Hz, the radeon high side power will remain around 4.7 - 5 Watt during idle at any desired resolution.

 

[Emiespo]

Hi guys, I want to share my settings for two Dell U2715H (QHD) monitors, in case it may help someone else.

I was losing hope: despite trying many different resolutions/combinations (SwitchResX) I couldn't get my MBP (16'' 5500M) not to bump to 20W as soon as even one single external monitor was connected. I almost gave up, I use this machine for work and it was throttling down to 1Ghz whenever compiling something, becoming not only slower than the former 15'' model, but also practically unusable even for writing a simple email (1Ghz doesn't cope well with today's requirements...).

In clamshell mode only I finally found one (default) resolution that made the trick: 2048x1152@60hz (and a pixel clock of 162Mhz - the important bit):

...unfortunately that would be blurry (and give less room), given my monitors have a native resolution of 2560x1440 (QHD). I tried all the os-default combinations (they are either 50 or 60hz), and none worked. Then I saw FF89's post above (thanks!) and noticed that the 162Mhz working pixel clock was exactly half of the clock in GTF for the mode he used - (2560x1440).

Tried that as well, still 20W... eventually I tried to switch cables around, and finally (two usb-c to mini display cables) I got it working. Wasn't working with a Sandberg usb-C HDMI dock, it wouldn't allow me to set a custom mode with Switch-Res-X.

So also check your cables/dock... they seem to play an important role in this flawed hardware design.
My current setup works with this settings, very close to FF89's (one of the monitors is actually rotated by 270 degrees, but that doesn't really matter as it's just a visual transformation):

Finally I tried to set up the internal display with the exact same settings (and pixel clock!) but it won't work (display stays black), and despite the same frequency, power still goes back up to 20W (fans spinning high, 1Ghz instead of 4, etc.)

I also still have the infamous WebKit gfx bug when switching between internal and dGPU, that was reported 1 year ago and still not fixed by Apple... but that's another story.

I guess they don't care much about these laptops anymore, with the M1s already way above their performance (with 2 monitors...).

 

[fs454]

I ended up getting frustrated and doing the VRM cooling mod - where you stack some thermal pads on the VRMs so that they reach and dissipate their heat into the bottom shell. These are the chips delivering power to the GPU and CPU and are typically cooled on desktop setups and thicker gaming oriented notebooks.

No more fan when the monitor (Dell P2715Q 4K60hz via Displayport) is connected, and even when I have Photoshop, After Effects, Premiere, and Safari open simultaneously working on assets passing through all of them I'm only seeing a constant ~70% fan and more often seeing 3ghz+ clocks rather than the ~1.8ghz it'd settle into previously.


Still obviously getting the high radeon high side draw but this mod seemed to attack the cooling/efficiency aspect of that. Only downside is the bottom gets a little hotter in that area, but that's never bothered me with these. They already get hot from the factory.

 

[IceStormNG]

These are the chips delivering power to the GPU and CPU and are typically cooled on desktop setups and thicker gaming oriented notebooks.

They're also cooled in a lot of laptops that are comparable to the MBP16" (like the newer Dell XPS).

Still obviously getting the high radeon high side draw but this mod seemed to attack the cooling/efficiency aspect of that. Only downside is the bottom gets a little hotter in that area, but that's never bothered me with these. They already get hot from the factory.

If you run under continuous higher power draw, you should make sure, the rear of the laptop is slightly lifted from the surface. The reason is: Heat will get trapped behind and beneath the machine and make cooling worse over time. The machine draws in cool air from the rear in the middle and exhausts to the rear outer sides. The air drawn in in the rear mid is used to cool the VRMs. So at some point the desk gets hot behind the laptop and the fans are actually more cooling the desk instead of the machine.

Blue: cool air, Red: hot air.

It takes way longer than before, but the CPU will throttle at some point to protect the VRMs (like when exporting from Final cut or something similar demanding).

I solved this by designing and printing some small standoffs I put onto the machine to lift the rear a few cm. The Thermal pad mod + these is enough to never make it throttle even under continuous full load.

This might also help in keeping the fans silent as the VRMs are cooled more effectively.

Yeah, doesn't look sleek or "professional" but it gets the job done.

 

[fs454]

They're also cooled in a lot of laptops that are comparable to the MBP16" (like the newer Dell XPS).



If you run under continuous higher power draw, you should make sure, the rear of the laptop is slightly lifted from the surface. The reason is: Heat will get trapped behind and beneath the machine and make cooling worse over time. The machine draws in cool air from the rear in the middle and exhausts to the rear outer sides. The air drawn in in the rear mid is used to cool the VRMs. So at some point the desk gets hot behind the laptop and the fans are actually more cooling the desk instead of the machine.

View attachment 1750203 Blue: cool air, Red: hot air.

It takes way longer than before, but the CPU will throttle at some point to protect the VRMs (like when exporting from Final cut or something similar demanding).

I solved this by designing and printing some small standoffs I put onto the machine to lift the rear a few cm. The Thermal pad mod + these is enough to never make it throttle even under continuous full load.

This might also help in keeping the fans silent as the VRMs are cooled more effectively.

View attachment 1750201 Yeah, doesn't look sleek or "professional" but it gets the job done.

Totally, that actually looks pretty solid. More professional than my "prop it up with two equal height random desk objects" method for sure.

On the downside, realized I sliced my right speaker driver open when sliding a credit card in to pop the bottom panel off. Got a used replacement from iFixit coming but it'll be up to me to figure out how to deal with both taking the current speaker off (it's all adhesive) and using Tesla Tape to hopefully securely attach the new one. Fun stuff. Protip, don't stick anything more than a quarter inch into the gap when trying to pop the bottom panel clips.

 

[koziolk]

However, using custom resolution of SwitchResX helps the situation in clamshell mode. Any kind of connection either USB-C to USB-C, DP to USB-C, or HDMI to USB-C cables to the MBP, as long as I enable "use simplified setting", GTF, and scan rate of 59.950 Hz, the radeon high side power will remain around 4.7 - 5 Watt during idle at any desired resolution.

Thank you for this clarification. What kind of connection are you using now? Is this DP to USB-C?

 

[FF89]

Thank you for this clarification. What kind of connection are you using now? Is this DP to USB-C?

At the moment, I use USB-C to USB-C cable if I want to charge my MBP (and to use with other peripherals connected to the monitor for example printer) or I will switch to DP to USB-C cable when I want to discharge the battery of the MBP while using the monitor.

Update: My new office monitor just arrived today. It’s a Dell U4320Q 4K USB-C monitor (found it during window shopping last week, it is a Dell’s refurbished monitor. Caused me about USD 550 after conversion from my country’s currency. Guess what? at 4K 60 Hz resolution (either connecting with USB-C to USB-C or DP to USB-C cable, my MBP radeon high side power does not spike to 17-19 Watt during idle without applying Custom Resolution of the SwitchResX . It stays around 5-6 Watt. I just changed the resolution from system preferences > display to make it work. However, it still only work in clamshell mode ?. I wonder why.

 

[koziolk]

Update: My new office monitor just arrived today. It’s a Dell U4320Q 4K USB-C monitor (found it during window shopping last week, it is a Dell’s refurbished monitor. Caused me about USD 550 after conversion from my country’s currency. Guess what? at 4K 60 Hz resolution (either connecting with USB-C to USB-C or DP to USB-C cable, my MBP radeon high side power does not spike to 17-19 Watt during idle without applying Custom Resolution of the SwitchResX . It stays around 5-6 Watt. I just changed the resolution from system preferences > display to make it work. However, it still only work in clamshell mode ?. I wonder why.

Looks like MBP works better with 4K resolution and with the newest monitor? ?
I think I would start looking for two 25" 4K or one curved 34" 4K UCB-C compatible monitor.

 

[tzamora]

Hi, I just wanted to report that I updated Big Sur and I think this fixed the problem for me.
I have the macbook pro 16" 2019 and use two U2520d monitors, this issue was very annoying had lot of fans noise and had kernel_task process with over 1500% cpu that got the OS unresponsive so I had to disconnect the monitors.

But now these issues seems to have disappeared I can use the original usb-c monitor cables and use accessories on all the ports at the same time with the macbook open no clamshell.

Edit: I also did the SwitchResX trick to change the hz of the monitor to 55hz, check my comment below.

 

[koziolk]

But now these issues seems to have disappeared I can use the original usb-c monitor cables and use accessories on all the ports at the same time with the macbook open no clamshell.

Great to hear this. What is your power usage on Radeon High Side in MPB open and in clamshell mode after Big Sure update?

 

[tzamora]

Good to hear that. What is your power usage on Radeon High Side in MPB open and in clamshell mode after Big Sure update?

I installed iStat to check ... in clamshell mode with middle-heavy usage it stays in 8-9w while opened 22w on average, I'm new in this thread, should this change on wattage be normal? Isn't just that three screens require more power?

 

[Spectra456]

I installed iStat to check ... in clamshell mode with middle-heavy usage it stays in 8-9w while opened 22w on average, I'm new in this thread, should this change on wattage be normal? Isn't just that three screens require more power?

Actually, no. Can you try it only with 1 external monitor?

 

[koziolk]

I installed iStat to check ... in clamshell mode with middle-heavy usage it stays in 8-9w while opened 22w on average, I'm new in this thread, should this change on wattage be normal? Isn't just that three screens require more power?

Are you running 3 screens (2 x U2520d with UCB-C)?
8-9w looks good in clamshell mode with 2 external screens, should be around 4-5w with one external.

 

[tzamora]

Are you running 3 screens (2 x U2520d with UCB-C)?
8-9w looks good in clamshell mode with 2 external screens, should be around 4-5w with one external.

Yes 2 dell monitors with their respective usbc cables and the macbook pro screen

Actually, no. Can you try it only with 1 external monitor?

Ok thanks to this I have noticed something, I have the SwitchResX with the 55hz hack. If I disconnect one of my monitors switchresx configuration changes and remove the 55hz limit setting the default 59.88hz
When this happens both clamshell and opened gives me the same: 22W aprox

I did the 55hz hack weeks ago but it didn't worked, yesterday I updated Big Sur but forgoted about switchresx.
the swithresX 55hz hack gives me 9w average in clamshell and 20w opened.

So I guess the issue is still there but at least the throttling let me work with all the screens I have.

 

[Spectra456]

Guys, is it possible to set some power limits for amd gpu? Maybe from bootcamp?

 

[kelvincht]

Hi, I just wanted to report that I updated Big Sur and I think this fixed the problem for me.
I have the macbook pro 16" 2019 and use two U2520d monitors, this issue was very annoying had lot of fans noise and had kernel_task process with over 1500% cpu that got the OS unresponsive so I had to disconnect the monitors.

But now these issues seems to have disappeared I can use the original usb-c monitor cables and use accessories on all the ports at the same time with the macbook open no clamshell.

May I ask which version of Mac OS have you updated?

 

[tzamora]

May I ask which version of Mac OS have you updated?

macOS Big Sur 11.2.3 (20D91)

 

[koziolk]

Ok. Last week I gave my MBP 16" on service. They decide to replace the motherboard as part of warranty.

Once I get the laptop back, I can write how it behaves.

Has this helped?

 

[Spectra456]

If you have only 1 display you can use AirServer(need to connect display to PC) to connect to your display via airplay. Everything is awesome, except framerate, Airplay supports only 30 fps((