MacBook 16-inch Fan Noise

Summary of the fan noise issue at MacBook Pro 16 inches:

1- First customers notice fan crazy issues ( loud noise) and overheating of the laptop middle November at only searching browse without any special demand to the device.

2- All MacBook Pro’s 16 with all type of configurations have the same behaviour.

3- This behaviour is appearing as soon as an external device is connected to the USB C interface. (Display in general). Some single cases appears the issue without any connection.

4- Therefore all MacBook Pro’s 16 are defective.

5- No communication from apple so far. It is not known if this is a hardware issue or software issue. Or both.

6- The recommendation is to return all the MacBook 16 within the 15 days guarantee. The one who keep it after the returned period will need to deal with apple, in something that two months after the issue appears has not been answered.

• Is there something that I missed?.

So I have made some further testing:

• With another external display (HP Z32) connected through usb-c cable with laptop lid opened: 20W radeon power consumption, fans ~3000 RPM, 65-70C CPU and GPU temp, fans audible
• With HP Z32 connected AND laptop lid closed: 5-8W radeon power consumption, fans ~1800 RPM, 50-55C CPU and GPU temp, fans inaudible - BUT sometimes I have to disconnect the usb-c cable and reconnect again, because Radeon gets stuck at 20W and would not drop to 5W
• With no external display connected: Radeon 0-3W, fans ~1800 RPM, 45-50C CPU and GPU temp, fans inaudible...

All tests were made during regular work (web browsing, coding) with ~10% CPU usage.

I was not able to get to less than 20W before on a different usb-c 4K display with lid closed so I am wondering if this was fixed by recent update to 10.15.3 or it depends on a display. Will test more when I get back to my other LG 4K display where Radeon was constantly drawing 20W even with lid closed.

The downside of using laptop in clamshell mode is that I cannot use fingerprint reader to unlock password manager etc - so back to good old password typing like on my previous 2013 15" MBP... At least I don't constantly smell the burning metal from heatsinks being cooked at 70-90C for whole working day...

William, You are logic is fundamentally flawed.

Following your logic it is perfectly fine for apple to design a new laptop that have a super powerful, overclocked CPU that is 1000W which could toast anyone holding it and drain the battery within a minute.

Your arguments would be:

1. The processor is incredible fast, so it will draw power very fast. And there are never anyone using the same CPU before
2. Apple never claimed that the battery would last any longer than 1 min, so it is normal and acceptable
3. Apple never claimed that you should hold it on your lap while using your laptop, so it is your fault and you should never hold it like that.

Use your common sense.

William, you're being ridiculous. It doesn't matter the REASON the laptop is to loud. If it's too loud, it's a poor design. And if you're trying to imply that in 2020 it's just not possible to design a silent laptop like in 2010, because modern processors can't function in laptops, then you need to start looking around at other 2020 laptops. By your logic, no one has any grounds to judge any feature of a laptop at all - OK, we have your opinion, it's not useful, because we're all trying to find a way to make an existing laptop work.

In any case, this is a serious problem that hopefully has a technical mitigation, and the purpose of this thread is to find help for the problem, not philosophize as to whether or not people have a right to be upset about an issue. If you don't have the issue, then that's valuable information in itself, and that's the limit of what you can usefully contribute to this thread. Thank you.

• Jeff

I ran some more tests at home. If I use the a non apple charger at home the watts are barely anything on the Radeon High Side or the intel gpu. this is also with the iPad being used as a side-car display. I'm also playing a youtube video. I wonder if the cord changes things.

heat is not an issue for me but it still is interesting how a single monitor plugged directly in clearly changes things.

Here is what I see and observe:

1. 16" MBP computer is using it's own display it runs at a cool 41 degrees, radeon high side (RHS) .08W, fans off
2. 16" MBP computer is using it's own display and sidecar 12.7" iPad pro it runs at a cool 41 degrees, radeon high side (RHS) .08W, fans off (same as above). Plugging in the iPad to the computer did not increase temp.
3. 16" MBP computer is using it's own display AND 1 4k plugged into MBP TB3 port 66 degrees, radeon high side (RHS) 20.47W, fans run low to low medium.
4. 16" MBP computer is NOT using it's own display (CLAMSHELL MODE) AND 2 4k displays plugged into CalDigit TS3+ dock, 69 degrees, radeon high side (RHS) 7.76W, fans run off to low.
5. 16" MBP computer is NOT using it's own display (CLAMSHELL MODE) AND 1 4k displays plugged into CalDigit TS3+ dock, 1 plugged into TB3 port on computer, 69 degrees, radeon high side (RHS) 7.76W, fans run off to low. (it's basically the same as with both screens plugged into dock.

This looks software/driver related to me and I can see where people might be running into problems. I would never have noticed if it wasn't for you guys pointing out the wattage difference.

I do wonder too if the Mac can tell if it's using an Apple charger vs another charger. There are so many variables nowadays that it can be difficult to know what exactly is causing the problem. I also wonder why my computer is running so much cooler at home than at work, though I don't think 66 is that hot, but still significantly warmer than the 45 that I'm getting at home. I've even got the same programs open + a video playing at home, that I didn't have at work.

To be fair, that's the issue with third party apps like iStat.

All sorts of devices have sensors to report all kinds of statistics, but when using an app like iStat, you are assuming that:

1. The app is reading the appropriate parameters correctly
2. The parameters reflect the actual values of what they are purported to

For example, Motorola PowerPC processors had a lot of sensors to report temperatures, but the implementation notes for those diagnostic fields stated that they should be calibrated per-processor (as they weren't accurate from one processor to another) and then should only be used as relative values (e.g. the temperature is now higher than it was, but not necessarily as much higher as this value and the last read would imply.)

Further, some sensors may report values that would ordinarily need to be enabled or hardware trimmed to be usable, and if Apple doesn't make use of them, they may not bother.

This is in no way meant to disparage iStat or other third party apps (or the issues people are having), just to note that the values they report may not be as accurate as one might think they are.

The admonition not to necessarily trust the values reported is borne of engineering experience, not just of opinion.

1. temperatures are NOT the main problem, they are merly the result/ side effect of another issue.
2. Temperatures while the crash where 70c yes, with fans on 100%, and cpu workload 25% - editing image sequence - can i actually do some realy work with this machine?
3. its GT pro not iStat
4. in the call today again been just repeated everything over and over again: do a full restore, smc reset, pram reset, add and test each app separatly etc - what i ve been doing for a month now. So dissapointed, i am not a tester, bought this to work not to setup my machine from scratch every week.

I am with you TailsDog.

I get how some people just want to bash Apple; most everyone here I have been listening to since this thread started have just wanted to receive some acknowledgment regarding a genuine performance issue that is not normal. Dispensing with the technical details, this is why we are here on this forum.

• It is NOT normal nor expected behavior for my new MacBook Pro to immediately begin to get hot the minute I plug it in to an external monitor with the lid open. There is a reason this happens, and it can't be the way Apple designed the machine to operate. If it is, I ask please for an Apple representative to let us know that this is the way it is supposed to sound when plugged into an external monitor, under these conditions.
• There are workarounds to this problem that result in the fans coming on at a higher temperature, or to disable turbo boost which allows the system to run cooler. These however, at least at this point in time, are workarounds and are not at this point acceptable long term solutions, again, unless Apple comes out and claims this is how it was designed to operate.

I have been using Apple computers since I was in college in the early 80s, including every year's iPhone since 2009 and new MBPs since 2006, replaced every 3-4 years on lease. Apple is slow to acknowledge real problems with their gear, so we want to make sure we properly communicate the issues we are experiencing. If it is not happening for everyone, great! I am genuinely glad not everyone has to deal with this. If you run an external monitor with the lid open (and perhaps have the 5500 GPU), it seems you likely experience this issue.

To everyone - to repeat, if you don't have this issue, great to know; it helps us to understand the scope of the problem. Thanks for your understanding otherwise.

I just want to summarize so far what I am seeing:

Symptoms:

When using an external monitor and no major processes causing load

• Big power increase for dGPU - runs around 20w
• Big temperature increase 30c+, fans spin up, area above touch bar very hot to touch
• Occasional temperature spikes to 90c+ for no apparent reason (activity monitor shows no high load processes)
• Activity monitor sometimes shows very high GPU time for WindowServer
• iStat shows dGPU memory filling up, sometimes 10 minutes after power up also shows spikes to 100% for dGPU processor
• When running processes that do push the system GPU and CPU things can be unstable, graphical glitches and sometimes crashes.
• Touchbar can hang when very hot
• dGPU causes blue effect on dark or light lines when True Tone or Night Shift is active (this maybe unrelated but it does not happen with the integrated graphics)
• Reports that using windows on bootcamp also causing high temps

What I've tried:

• Deactivating background processes, syncing, indexing etc
• Safe mode
• Different cables
• Turbo Boost Switcher
• Less apps running, less browser tabs not playing video
• Different resolutions
• Frequent reboots

What seems to work:

• Not using an external monitor
• Using an iPad with sidecar for an extra display
• Using an eGPU
• Clamshell mode, lid shut connected to keyboard and monitor(s)

Bryce, I saw you said you run in clamshell and not, do you have the 5500M?

• Would you mind letting us know how much RAM and video memory your machine has?
• Would you mind letting us know what happens to fan speed if you plug in a monitor with the lid open and just let it sit for 5 minutes, no activity?

Mine gradually goes up from under 2000 (which is almost silent) to over 3500, with no activity. iStat reports "Radeon High Side" at over 19W all the time it is plugged into an external monitor, never lower.

Curious if this is just happening to a few machines; I would love to be able to swap it out for one that doesn't do what mine is doing.

As I understood the problem is either partially or completely solved using CalDigit TS3+. Is it true?

If it is true, in which mode, the behavior of the notebook is the closest to what we expect from a simple connection of an external monitor:

• One monitor is connected via CalDigit TS3+
• One monitor is connected via CalDigit TS3+ in clamshell mode
• Two monitors is connected via CalDigit TS3+
• Two monitors is connected via CalDigit TS3+ in clamshell mode

I use CalDigit most of the time. So, I have the following:

1. No difference, high wattage and it is hot
2. Works properly (tested on 2K, 4K and a FullHD monitor), corresponding to the iStat consumes approx. 5-6 watts
3. The same as 1.
4. The same as 2. (the combination of displays make no difference)

The only one issue I have with the CalDigit: if the MBP goes to the sleep mode at his own (after e.g. 15 Mins), after waking it up no output to display before reconnecting the cable manually. If you send it to sleep mode manually, everything is fine.

I also have an USB-C adapter and tried to connect a display using HDMI, using this adapter no mode helps, it always consumes approx. 20 watts.

Hi,

I also experience the same problem. I have a LG 5K2K Display connected to a Belkin TB3 dock.

MacBook Pro 16" is connected to the dock by TB3 cable.

when I connect it to the dock the fan will spin up and when I look on the temperature I can see that the "Platform Controller Hub"

and "Thunderbolt port" temperature goes up quite fast. The temperature management seems to take the highest of all measured temperatures and try to cool it down, even if CPU and GPU temp is low.

I made a test:

1 - nothing connected to TB3 ports:

• • Platform Controller Hub: 64°C
  • Thunderbolt port left: 35°C
  • Thunderbolt port right: 35°C

2 - TB3 dock connected to left port:

• • Platform Controller Hub: 65°C
  • Thunderbolt port left: 51°C
  • Thunderbolt port right: 35°C

3 - connect 5K2K screen to TB3 dock:

• • Platform Controller Hub: 75°C
  • Thunderbolt port left: 61°C
  • Thunderbolt port right: 36°C

So I guess the reason for the fan noise, when connecting an external screen, is the temperature going up in "TB3 ports" and mostly on the "Platform Controller Hub".

If I set manually the speed of the fans to 3000-3200rpm the temperature of the Hub never go over 74°C, so here Apple can improve the Fan management a lot. Simply use different priorities for the different temperature sensors.

Cheers!

This thread is titled "MacBook 16-inch Fan Noise" - boiled down to its essence it is about people experiencing great amounts of heat when using an external display and a symptom of that is loud fan noise.

It is probably good that people should know about the product so that they can make an informed choice before a purchase. So far we have seen posters with varying degrees of problems:

• Excess heat with extreme temperatures when machines are under very low load causing constant loud fan noise.
• Graphical glitches when temperatures go up.
• System crashes when temperatures go up.
• Touchbar crashes when temperatures go up.
• Fatal device malfunctions when temperatures go up.

I am facing several Bugs with my new Macbook Pro 16 i9 AMD Radeon 5500M:

• Blue Pixel Tint on internal and external display with AMD on
• Drains constantly 20w Power with AMD on when connected to external display in idle
• Drains 10w power when AMD Radeon with only internal display on in idle. Cant deactivate discrete graphis, so battery drains fast even when you dont need the power like with sketch or some chrome sites in idle, they turn AMD on.
• This leads to hot MBP 16 and fans noise even while doing normal low cpu stuff like internet and sketch design. 2015 MBP was dead silent.
• Throttles CPU 10% with AMD (just because connected to external monitor, 20w AMD power supply!) while heavy cpu load (video conversion)
• Drains constantly battery under heavy load like video conversion in handbrake while connected to Power (140w peak Power and 100w+ permanent use)

This MacBook AMD Combo is still beta.

Will return my 2nd MBP 16 tomorrow and wait until apple fixes these issues and buy again. They had enough time and evidence. So i think they cant or dont care.