MacBook 16-inch Fan Noise

The only solution currently is to buy the 5600m version of the MBP 16" the 5500m and 5300m have a power issue with the gpu causing a high gpu load thus high fan speeds.

We've gone into technical detail on the MacRumors forums on this.

The information gathered points to a hardware issue with the AMD GPU, and Apple not allowing the onboard Igpu to drive low video out loads as the 930 UHD can drive 3 4K monitors.

Best thing to do is disregard the censorship on this forum (Apple deletes posts) and call apple and complain. Overwhelm them to do something.

I can confirm significant CPU performance hits with dual display. The thermals of the GPU running at 20W+ is now knee capping my workflow.

Adobe Lightroom image export - left is with a single LG 5K display connected, right has a Dell 2560x1600 display connected as well.

The CPU performance falls off a cliff in the dual display configuration, yet still remains at 65 degrees C. With a single display, I see the CPU hit around 80c, suggesting we are seeing a power delivery problem, or an over-zealous software-based thermal throttling workaround implemented in the OS, that's clearly aware of the Radeon's power draw, and kneecaps the CPU to prevent molten lava.

What's really interesting? I'm seeing a 40W consumption difference on the CPU, which is more than the 15W delta we see on the GPU... there is something very unusual going on with the power delivery mechanics of this system that seem to extend beyond thermal throttling. At least I've now identified the cause of almost all of my performance issues!

I'll be logging this with AppleCare tomorrow.

After playing around with an awful lot of 3rd party apps & wasting a lot of time, the combination of the following worked for me to drop the power of the dGPU from around 18/19W down to around 5W and thus avoiding the fans to go off with tasks like browsing/emailing.

Install SWITCHRES X - set the refresh rate from the monitor from 60HZ down to 55HZ (in my case) and leave the macbook closed in clamshell mode.

I really hope that apple comes up with a fix, super annoying and clearly not well done from their side as I can't imagine that a drop of 5HZ will also drop the dGPUs power usage by 75% :-/

That drop in the refresh rate may drop the memory-speed requirements.

When the Display memory can be run at low speed, it drops power consumption by about 10 watts or more.

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This is a really GREAT tip, because the difference to your eyes of 55 versus 60 is not much, but the 10 Watts is golden.

What resolution is your display, and what interface ? {HDMI or DisplayPort family}

In my case is the opposite, I partially fixed the issue by changing the refresh rate to 144 hertz, this is on 10.15.4, on other versions it doesn't work like it does on this version, for example on 10.15.5 if I watch a YouTube video the watts will go over 30 watts and the machine will get crazy, on the other hand on 10.15.4 will stay between 10 to 18 watts and the fans never go over 2000 RPM.

so guys here's my setup and how I managed to get this laptop always below 70C and with a healthy battery

1. installed turbo boost switcher (with a mod that prevents it from asking the password every time) and turned off turbo boost (I don't really see a difference, if I hit 100% cpu on an Ableton project which is the only pro app I use then I will re-enable it)

2. bought a stand to have a better airflow when docked

3. installed mac fan control and setted fans to run at 2.5k rpm every time I connect the laptop to an external monitor (the laptop isn't so close to me so I don't even hear anything plus I'm with headphones the majority of the time)

4. installed SwitchResX and with some custom settings managed to get the radeon at 5watts when idle in clamshell

5. installed charge limiter which is an app that allows you to limit the max charge of the laptop (I stetted mine to 80%) since I use the laptop plugged in 95% of the time, this resulted in still 98% battery health in 7 months of usage, and if I know that I'm gonna need a 100% charge for the day I can disable this limit in a matter of seconds

with all this "tricks" I get an idle temperature of about 45C, 50C when watching a YouTube video and from 60C to max 68C when doing pro stuff (in my case music production with Ableton Live). Consider also it's July, I live in italy (very hot in this time of the year) and I don't have AC in my room. If I'll ever hit 100% cpu I will re-enable turboboost but for now I'm happy like this. Yeah not being able to use the laptop monitor while plugged to an external is a bummer but I got used to it and lost any hope in a fix at this point

Now I wish I could upgrade to the 5600m model as it seems to consume much less power with lid open. I've used my MacBook Pro's with an external display for years in open lid mode. First with the Apple Thunderbolt Display and then the LG UltraFine 5K, the latter I currently use with my 16" inch with 5500m. With the lid open, the Radeon locks to 18+watts and the laptop quickly heats up and fans pick up - 2k, 2.5k, 3.5k RPMs eventually getting to 4.5k RPMs and higher, all while simply browsing the web and having Outlook open. Close the lid, and within 1 to 2 minutes the temperatures subside and the fans go back down to 1,800RPM and stay there under general use. Radeon power drops to 4 to 5 watts. Really frustrating. I'm not posting anything new, but adding to the list of people who can confirm similar behavior with external display and lid open.

I don't understand why powering the additional laptop display would require 3 times more GPU power. This is what makes me stay optimistic that a software patch could fix this or at least help significantly.

I think it's fair to say that most users ARE experiencing heat and fan noise issues when connecting an external display. Your continued defence of Apple's "expected behaviour" line is, to be honest, a little tiresome. Your use case seems to be OK. I'm glad for you, really I am. For many others - certainly the majority on this thread - that is not the case.

I maintain that it is not reasonable to expect a premium laptop to suffer the level of heat and fan noise that the 16 inch MacBook Pro does when used with an external display with the lid open.

I've found a workaround that I'm happy with - clamshell, in a vertical stand with vents pointing up, Turbo Boost disabled. However I had to spend extra cash on external keyboard, mouse, microphone, webcam and speakers to achieve this and be able to work and do Teams video calls professionally. It now runs silently for me in this mode so I am sticking to it. However I should not have had to do any of this. My "expected behaviour" was that the laptop that cost me well over £2k would be able to handle connecting an external display while allowing me to use the features I bought it for - the excellent keyboard, speakers and mics. The fact it doesn't is not really acceptable.

+1 on this topic.

I had to install & buy Turbo Boost Switcher Pro in order to deactivate automatically Turbo Boost when needed.

Since then the MBP16 is running below the 60 Degrees without any side effect.

Giving the fact I manage to solve the issue myself (thanks to this forum by the way) I can imagine that Apple would be able to do the same. However as of today, none of Apple CustomerCare or Genius Bar have been able to provide any resolution (despite the numbers of comments in this post ...)

It is, here’s a video of the MBP 16 I had, running idle at 4300rpm with two external monitors.

https://youtu.be/hkVkKmP-jY8

Unplugging one one the monitors was dropping the rpm back to 2000rpm.

Unplugging all monitors and we’re back to ~1700rpm and complete silence.

So let people share their experience and find solutions instead of calling them liars.

Long time observer of this and MR thread (https://forums.macrumors.com/threads/16-is-hot-noisy-with-an-external-monitor.2211747/page-124). Tried every single possible resolution and refresh rate, even different monitors (can't remember all the models), not a change. Every single time, GPU eats around 19W (simply switched memory to the highest performance profile and thus wasting thermal capacity of the machine). As others has pointed, this can't be accepted as okay. why waste so much power on redrawing just a single monitor not to mention is not even 4K? Older GPU models (heck my previous MPB 15" 2017 was more efficient) handled such tasks with less power used.

Anyway here's what I have and have tested with the every possible option:

MBP 16" base configuration (i7 2.6, 5300M 16GB RAM)

Display Dell U2713HM connected via https://www.amazon.com/Displayport-QGeeM-Thunderbolt-Compatible-MacBook/dp/B074V5MMCH directly to either side of MBP.

Connecting external display causes GPU to immediately draw around 19W and temperatures go up and stays above 60 Celsius for both CPU & GPU - leaving way less thermal space for when it's needed.

Another example - having iPad Pro connected to the mentioned monitor can handle rendering the screen much more effeciently than MBP. I understand it's mixing apple and oranges here, but still - isn't it obvious enough that it is a problem?

As long as the title of the topic remains "Fan Noise", we won't see the solution soon.

Why? because I guess that most of the members are calling to Apple support and don't describe the issue as needed.

Fan noise is something usual among computers, and among MacBooks as well.

The real issue is the high GPU watt usage with the external monitor while the lid is open, which leads to fan noise.

In case you didn't describe the issue as I wrote, call Apple support again and make sure you open a new ticket.

We must bring this problem into consciousness in every way possible, be precise in formulating the problem wherever you present it, and only then will change appear.

Just chiming in here to confirm:

The issue happens, too, if I connect the Macbook Pro 16" to my Samsung U28E850. Radeon High Side goes up to about 19W power usage and the fans spin up within minutes.

The issue does not exist in clamshell mode. But this is suboptimal as that way I loose Touch ID which is a nice benefit of this device.

As a quick clarification, simplifying the overheating issue to simply "it's a more powerful GPU" is not a valid assessment of the issue. Any metaphors involving sports cars are entirely off base.

The problem is not as simple as "more pixels = more energy" or "faster refreshes = higher energy" or even "newer GPU generation = more energy". It is far more detailed and far more nuanced.

Once again, to quote an AMD employee (emphasis mine):

Multiple displays with different resolutions, refresh rates, timings and or using different display adapters/connections requires more resources from the GPU, this can move the GPU up into the next memory clock state to compensate and avoid issues such as flickering or corruption.

As some in this thread (and on other forums) have shown playing with the settings outlined in that quote (resolution, refresh rate, display adapter, etc.) have had dramatic effects on the GPU's energy usage. It is entirely possible to run a 4K monitor on one of these systems and see 5W GPU power consumption while an old 2K monitor draws 19W - the difference lies somewhere in the bag of settings/connections between the monitor and desktop.

As this is a known issue and expected behavior for Apple, it would be nice to have some guidance as to what settings/adapters/monitors (or combinations thereof) are known to work best.

To those who would simplify the issue to "hot-rod GPU = high energy usage", I think a better approach to helping people would be to ask after their monitor setup details and perhaps suggest some adjustments to see if that helps them.

Please stop oversimplifying this. It doesn't help anyone.

[Side Note: I have a 2018 15" MBP with two external monitors - 1@4K, 1@2K. With my standard setup, the Radeon High Side draws ~15W of power. If I simply rotate one of the monitors (I usually keep one in Landscape mode), that power usage changes (I've seen 19-20W usage depending upon settings as well). The fact of the matter is that this power draw/heat generation is not limited to the GPUs in the 16" machines - it may simply be that they are less good (or less quiet) about getting rid of the excess heat. Given that the GPU in the 16" is 'far more powerful' than those in the 2018 15" and yet have the same exact power draw, I think we can agree that the car metaphor should be put to bed.]

ryunokokoro wrote:

You're oversimplifying the point here by reducing the complexity down to "high clock speed". Telling people "well, your configuration has high clock speed because you're on a super powerful GPU" isn't helpful. Telling people "the GPU in your system has a quirk where your configuration (connection type + display settings) may force your GPU to run much faster than expected" is helpful.

Though it's not actually a "quirk," but rather according to AMD it's by design.

People are coming to this thread for help. Telling the "you're the one who opted for a super powerful GPU" won't help them. Explaining the source of the issue and why they may be seeing unexpected results will give them a fighting chance to try some changes to their setup to alleviate the issue.

Which I and others here have done by showing our experimental data.

I think you will need to restate the reasons you've given as your "defense" tends to fall back on "if you want a laptop that doesn't start up fans with an external monitor, buy one without a discreet GPU".

If you're trying to help people, you shouldn't be on the defensive to begin with.

You characterize my answers as "defensive" but that's not my approach at all.

Rather many here use the term "defective," which has a specific meaning which is not applicable here.

Instead the machine is performing a way other than they would prefer for the task and configuration at hand, and it is caused in part by the tools used to do the job. I have stated where I believed another selection would do the job at hand better.

That is exactly the wrong question. This is exactly why you aren't helping. There are people out there who could get the silent fans they desire by simply adjusting their refresh rate from 59Hz to 60Hz (or vice versa, depending). What do they give up? In this case, they actually gain in refresh rate and achieve their "silent fans" goal.

But at the potential cost of flicker and graphical corruption, at least according to the manufacturer of the GPU. That is also a "cost" that must be taken into account.

HBM uses lower clock speeds when compared with GDDR memory. It makes up for that speed difference by having a much wider memory bus width (2048bit vs 128bit [or lower]). Assuming that the same "certain configurations require faster memory access to handle" applies to the HBM-based architectures, then even if they run at a faster speed they require less power to do so and therefore generate less heat. That said, the issue could also have been handled in some other way. We just don't know (and likely never will).

Indeed, and advantages like this is why HBM2 was developed; the downside is, of course, higher cost.