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

[akunno]

Well after hours I got mine working.

I have two Kogan 27" 2k monitors @ 59.88 hz or 74.99 hz, and an Asus 2k monitor @ 60hz or 75hz according to the displays tab. Hub is a Plugable 14-in-1. All cords are 8k compatible, DisplayPort 1.4.

(Mac is an i9, 5500M like everyone else who's had the issue)

With the MacBook in clamshell mode, all 3 monitors connected or independently, the radeon hits 18w.

After using switchresx, I have tried lowering and increasing frequencies. e.g. the Kogan monitors should be 60 and 75hz. Forcing them to this resolution does not fix the issue, and I can confirm the issue isn't fixed if running the monitor on it's own even if using GTF.

However, I had success on one monitor when setting the refresh rate to 57.886 hz. The magic number is whatever ends up having the pixel clock "close" to 300 MHz. I applied the same to the Asus (57.87 Hz) and now I have a very stable 6.9w of power draw.

I have contacted apple (outside of AppleCare, unfortunately now) but will be showing them that increasing or decreasing the frequency 1hz is causing the wattage to suddenly jump to 18w - hence this seems very likely a software issue.

I hope the above helps someone else. I'm still not confident a restart will restore the frequencies correctly (I seem to need to do it manually, as SwitchResX isn't applying it on load) but at least the system is working now.

EDIT: After my second reboot, the same settings now jump to 18w. Not sure how to force it to work again - clearly a software issue though.

 

[randolorian]

I have this issue at times, throttling to 1GHz during some of my sessions. Please do report back if you find out anything. A restart usually fixes it for me, so I haven’t bothered taking it into the store yet.

Are you using a TB dock? Try disconnecting and reconnecting the dock. This temporarily fixes the 1GHz issue for me. I’m using a CalDigit TB3 dock

 

[Tribune]

I just tried a DisplayLink adapter to connect my second monitor (Dell P2421D). My main screen is a Dell 2720Q connected via USB-C. The radeon drops to 5-7W instead of 20W. Unfortunately, the screen recording settings required by the DisplayLink adapter disables Netflix (audio works but black screen). I guess this is the case for all these adapters?

I wanted to try if this setup works reliably to prepare my switch to a M1 Macbook.

 

[francojay]

I'm on a 2019 16" MacBook Pro, and Big Sur OSX 11.2.2 "20D80" fixed my CPU spike issue. Whatever they did, it helped significantly with the CPU handling. Now I'm able to use my two ultra wide monitors along with my laptop screen. No need to force clamshell mode. I would suggest everyone to try this update.

 

[sg9]

I'm on a 2019 16" MacBook Pro, and Big Sur OSX 11.2.2 "20D80" fixed my CPU spike issue. Whatever they did, it helped significantly with the CPU handling. Now I'm able to use my two ultra wide monitors along with my laptop screen. No need to force clamshell mode. I would suggest everyone to try this update.

What's your GPU power draw?

 

[spachner]

Can confirm that Big Sur OSX 11.2.2 has positive effect on my fans (MacBook Pro (15-inch, 2016) connected to an old 27" iMac via DisplayPort)

 

[arobert3434]

If 11.2.2 allows sub-18W with lid open I might just consider moving to Big Sur early!

 

[Minga089]

If 11.2.2 allows sub-18W with lid open I might just consider moving to Big Sur early!

Very unlikely. There won't be any fix imo.

 

[asankhata]

11.2.2 didn't help in my case (MBP 16" AMD Radeon Pro 5300M).
Still Radeon High Side 18w+ when external display is connected.

 

[hedehodo34]

My company offered me 16" i9 or 16" i7 or 13" M1 for business use and they do not share the gpu model info. I am working as sysadmin for my company and I use 2017 13" macbook pro in clamshell mode with 1 external 4K monitor(LG 27UL850) in 2K scaled mode with usb-c connection. I also had fan noise problem with 2017 13" pro and fixed with disabling turbo boost mode. Is this problem only happens on 16" when lid opened? not happening in clamshell mode? I want to choose 16" because of x64 architecture and reverse compatibility but if clamshell mode doesn't fix the problem I will go to M1 route.

I received my mbp 16" I9 a week ago. In clamshell mode with external display(scaled to 2K on 4K monitor) a had zero issue. I do not have to disable turbo boost anymore. Fans are quiet, cpu and gpu is work like expected. I just wanted to share my experience

 

[spachner]

Can confirm that Big Sur OSX 11.2.2 has positive effect on my fans (MacBook Pro (15-inch, 2016) connected to an old 27" iMac via DisplayPort)

Have Radeon High Side before 11.2.2 and now unchanged at ~10W, nevertheless the fans are not that noisy anymore

 

[akalogiros]

Well after hours I got mine working.

I have two Kogan 27" 2k monitors @ 59.88 hz or 74.99 hz, and an Asus 2k monitor @ 60hz or 75hz according to the displays tab. Hub is a Plugable 14-in-1. All cords are 8k compatible, DisplayPort 1.4.

(Mac is an i9, 5500M like everyone else who's had the issue)

With the MacBook in clamshell mode, all 3 monitors connected or independently, the radeon hits 18w.

After using switchresx, I have tried lowering and increasing frequencies. e.g. the Kogan monitors should be 60 and 75hz. Forcing them to this resolution does not fix the issue, and I can confirm the issue isn't fixed if running the monitor on it's own even if using GTF.

However, I had success on one monitor when setting the refresh rate to 57.886 hz. The magic number is whatever ends up having the pixel clock "close" to 300 MHz. I applied the same to the Asus (57.87 Hz) and now I have a very stable 6.9w of power draw.

I have contacted apple (outside of AppleCare, unfortunately now) but will be showing them that increasing or decreasing the frequency 1hz is causing the wattage to suddenly jump to 18w - hence this seems very likely a software issue.

I hope the above helps someone else. I'm still not confident a restart will restore the frequencies correctly (I seem to need to do it manually, as SwitchResX isn't applying it on load) but at least the system is working now.

EDIT: After my second reboot, the same settings now jump to 18w. Not sure how to force it to work again - clearly a software issue though.

Can you please share from which point of SwitchResx you changed the refresh rate?
From the display information area, or you created a new "resolution" under "Custom resolutions"?

 

[schriker]

https://www.reddit.com/r/apple/comments/m0f4wl
Does this mean driver gpu update? May this fix heating issues?

 

[kelvincht]

I have found out the root cause of the issue.

The issue is GPU will have high idle memory clock around 1400-1500mhz and high power use when multiple monitors with different refresh rate is connected. However if only one display is used, memory clock can idle at <300 mhz.

With two monitors, I can manage to fix the GPU idle memory clock issue by have two identical external monitors in clamshell model, I need to use SwitchResX to create two custom resolutions profiles with EXACTLY identical timing parameters. For example Refresh rate, Front porch, sync width, back porch setting must be identical. Refresh rate must be identical. Like 59.9966 for both monitors. If one is 59.997 and one is 59.996 it will NOT work.

With build-in + external monitor, it won't work because the VSync timing will not be exact because of different resolutions. The GPU will default to high idle memory clock.

An technical article mentions there is a sync issue when monitors are in different timings and memory clock changes will cause screen tearing and artifacts. Their workaround is the set the memory clock at high setting to avoid memory clock changes.

I believe Radeon should be able fix it with few strategies:

1. Try to sync the monitors timing internally when multiple monitors are roughly the same refresh rate. For example 59.9hz vs 59.8hz should all be treated as 60hz internally.

2. Using human visual illusions masking strategies to migrate the visible the out of sync tearing artifacts when refresh rate is different

3. Allow dynamic memory clock, but rather than than adjust memory clock continuously, try to adjust the clock less frequently. For example if the adjustment is done every ten seconds, one lost frame every 10 seconds will not be noticeable to human eyes.

 

[IceStormNG]

I have this issue at times, throttling to 1GHz during some of my sessions. Please do report back if you find out anything. A restart usually fixes it for me, so I haven’t bothered taking it into the store yet.

Are the fans on full blast when this happens? Could be the VRMs overheating. They easily do that when the dGPU is active. Apple decided to not properly cool them. So they get hot very quickly and then the whole machine has to throttle because they cannot deliver enough power anymore.

There are some "fixes" for that. But it involves hardware modification.

If it's not that, it could be an issue with some peripheral your Mac doesn't like. There are some Thunderbolt docks that can cause various, weird issues.

 

[akunno]

I have found out the root cause of the issue.

The issue is GPU will have high idle memory clock around 1400-1500mhz and high power use when multiple monitors with different refresh rate is connected. However if only one display is used, memory clock can idle at <300 mhz.

With two monitors, I can manage to fix the GPU idle memory clock issue by have two identical external monitors in clamshell model, I need to use SwitchResX to create two custom resolutions profiles with EXACTLY identical timing parameters. For example Refresh rate, Front porch, sync width, back porch setting must be identical. Refresh rate must be identical. Like

Isn't this the default for two identical monitors anyway?
I also verified the same thing and it was still hit and miss. After my second reboot or resume from sleep, the SwitchResX settings were still applied, but the watts went back up to 18+ --- so I figured it wasn't working. I agree with the premise, but I suspect the hardware or software is still making a bad decision somewhere.

Further, with only one screen we should be seeing less of an issue - but unfortunately I've seen my Asus monitor working perfectly fine at 75hz, but then cause the weird glitch when I swap it to 60hz.

 

[akunno]

If I have a single monitor attached at 75hz, radeon is below 10w. If I change it to 60hz, it jumps to 18w.

However, I can confirm that @kelvincht is correct - setting all 3 monitors (regardless of brand) to the same resolution and refresh rate does indeed have the radeon at a paltry 5w. There's no tearing or flickering at all.

If I used a HDMI cord (as opposed to DisplayPort) then I did get the flickering on one monitor only.
So thank you. Persistence has definitely paid off in this case, and I have 3 monitors working fine in clamshell at least.

(Although it needs to be re-done every time the computer wakes from sleep...sigh)

 

[arobert3434]

I have found out the root cause of the issue.

The issue is GPU will have high idle memory clock around 1400-1500mhz and high power use when multiple monitors with different refresh rate is connected. However if only one display is used, memory clock can idle at <300 mhz.

With two monitors, I can manage to fix the GPU idle memory clock issue by have two identical external monitors in clamshell model, I need to use SwitchResX to create two custom resolutions profiles with EXACTLY identical timing parameters. For example Refresh rate, Front porch, sync width, back porch setting must be identical. Refresh rate must be identical. Like 59.9966 for both monitors. If one is 59.997 and one is 59.996 it will NOT work. View attachment 1740936

With build-in + external monitor, it won't work because the VSync timing will not be exact because of different resolutions. The GPU will default to high idle memory clock.

An technical article mentions there is a sync issue when monitors are in different timings and memory clock changes will cause screen tearing and artifacts. Their workaround is the set the memory clock at high setting to avoid memory clock changes.

I believe Radeon should be able fix it with few strategies:

1. Try to sync the monitors timing internally when multiple monitors are roughly the same refresh rate. For example 59.9hz vs 59.8hz should all be treated as 60hz internally.

2. Using human visual illusions masking strategies to migrate the visible the out of sync tearing artifacts when refresh rate is different

3. Allow dynamic memory clock, but rather than than adjust memory clock continuously, try to adjust the clock less frequently. For example if the adjustment is done every ten seconds, one lost frame every 10 seconds will not be noticeable to human eyes.

Your screenshot shows a refresh rate of 79.979, not 59.9966. In any case, refresh rate is an aggregate value while the frequency of the signal itself is the pixel clock of (in your case) 763.5 MHz. Is it this that needs to be synchronized? Will SwitchResX show what it is for the internal monitor, and then if you tweak the external settings to get the same value, will that take it down to 5 watts with lid open?

 

[stunpix]

I also can confirm @kelvincht is correct. I'm trying to use my MacBook with an external 4K monitor while the lid is open and once I copied resolution and timings from the internal monitor and applied them to the external (it accepts a wide range of resolutions and timings) the system power consumption immediately dropped to 16-20W while "radeon high side" itself to 5-6W. The only downside: the image on the external monitor is distorted due to incorrect resolution.

 

[TheRealAlex]

I received a base 16" today and am disappointed because it get's as hot as my 2017 with an external 4K monitor.

Is anybody else experiencing the same issue? I always work with external monitors and running on high resolution and this heating performance is upsetting. It's not cooler than the 2017 version in this respects.

Can you guys share your thoughts on this?

Thanks a lot!

Had this similar issue i7 16” MBP dual Monitors 4K was really heating up. Long story short. Apple Store duplicated the issue determined it was poor connection from the CPU to the heatsink. It was in Warranty at the time. Even got a Free Upgrade from a 512GB NVME Drive to a 1TB NVME drive since they had to replace the whole CPU motherboard assembly. They emailed me to authorize the upgrade I was like Heck Yes.

 

[kelvincht]

Your screenshot shows a refresh rate of 79.979, not 59.9966. In any case, refresh rate is an aggregate value while the frequency of the signal itself is the pixel clock of (in your case) 763.5 MHz. Is it this that needs to be synchronized? Will SwitchResX show what it is for the internal monitor, and then if you tweak the external settings to get the same value, will that take it down to 5 watts with lid open?

Hi Robert, I borrow that screenshot from switchResX website. My setting is 4k @ 59.996hz using CVT-RB(Reduced Blanking) timing standard.

I am also aware the total bandwidth of the resolution must be lower than the bandwidth of the Displayport/HDMI with a 5-10% margin. It is because the memory clock will be stuck to max if there is not enough blanking time for the memory clock to switch.


I really hope AMD can create a driver fix that tries to sync minor timing differences.
If that is not possible at least they keep the memory clock on two states - High clock and low clock.
Drop clock from high to low after 10 seconds of low screen inactivity, instead of changing the memory clock every milliseconds.
One lost frame every 10 seconds is much better than an overheated laptop.

 

[arobert3434]

I also can confirm @kelvincht is correct. I'm trying to use my MacBook with an external 4K monitor while the lid is open and once I copied resolution and timings from the internal monitor and applied them to the external (it accepts a wide range of resolutions and timings) the system power consumption immediately dropped to 16-20W while "radeon high side" itself to 5-6W. The only downside: the image on the external monitor is distorted due to incorrect resolution.

Hmm, I tried to do this by matching the settings shown in the screenshot but it didn't work. Note, in my case when setting on the external monitor the "Scale to" fields were greyed out, not sure if that makes a difference.

 

[jagooch]

I'm echoing everyone else with the new M1 chip Macbook Airs/Pros.

The 16" MBP is STRAIGHT OVERHEATING JUNK!

My new cheap Macbook Air M1 runs really cool with the exact same external monitor plugged in than my garbage 16" MBP that overheats if you look at it.

May I ask which external monitors you have? I spent a 3-4 weeks trying everything under the Sun to get my 16" Macbook Pro (2019 ) to not overheat with 2 4k LG Ultrafine displays connected. My troubleshooting thread is about 56 pages long, lol. I really tried everything that made sense and many things that did not. It never hurts to try!

Apple replaced the motherboard but that didn't fix it. I have to have the external displays connected through an eGPU to prevent the macbook from overheating.

My employer gave me the exact same laptop for work, and it also overheats with external GPU's connected.

I'm considering getting an M1 and use the 14 day return window test if it overheats like my Intel Mac. However I don't know if all of my apps are M1-compatible. I'll need to research that as well.

Update: I looked at the M1. You cannot get it with 4tb ssd storage , so it’s not even an option for me.

 

[prospervic]

It may be because the LG UltraFine 5k is specifically optimized for Macs, but I've gotten great results (less heat, far less noise, slightly better battery life) by simply turning off Intel's Turbo Boost with this app: http://tbswitcher.rugarciap.com

Marco Arment offers strong arguments for this: https://marco.org/2020/01/13/macos-low-power-mode-redux

 

[jagooch]

It may be because the LG UltraFine 5k is specifically optimized for Macs, but I've gotten great results (less heat, far less noise, slightly better battery life) by simply turning off Intel's Turbo Boost with this app: http://tbswitcher.rugarciap.com

Marco Arment offers strong arguments for this: https://marco.org/2020/01/13/macos-low-power-mode-redux

Turbo Switcher is one of the many, many things that I tried. It helps a bit but my Macbook still overheats with Turbo boost disabled.