MacBook Pro 16" overheating with external monitor

the problem is caused by the gpu ramping up to 18 watts as soon as a monitor is plugged (it should stay at around 5watts idle..), still waiting apple to solve this software bug, here's a thread that explains the problem better https://forums.macrumors.com/threads/performance-degrading-on-sustained-workload-w-external-monitor-mbp-16.2216009/

I have got the same issue with MacBook Pro16".

It's going hot, when I connect some external devices. Especially 2 external monitors it's going very hot and the battery is empty in less than 2 hours.

When I'm using my old macbook 2015 with the same devices, I don't have any issues. I already booked an appointment on Genius Bar.

My specs:

2.3 GHz 8-Core Intel Core i9

32 GB 2667 MHz DDR4

AMD Radeon Pro 5500M 4 GB

Intel UHD Graphics 630 1536 MB

1 TB Flash Storage

Same issue.

My MacBook Pro 16" also is overheating when connected to an external monitor with Type-C -> DisplayPort. Fun ~2600, temp ~61°C. Without external monitor fun ~1800, temp ~51°C.

In the previous MacBook Pro 15", 2018, no such thing was observed.

Apple please answer :(

That affects every macbook. I let my macbook repair in apply store, and they didn't do anything. The answer is: its normal behavior. Unbelievable. I didn't see any other notebooks, that going hot when using external monitors. It's definitely not normal. I'll never buy macbook again. That was my last macbook, I guess.

I was having the same issue, but it wasn't as extreme as OP's.

Connected via a usbc to HDMI cable, to a 2k monitor (Asus PG279q to be specific)

Temperature was looking at 60 -65 c when idle.

However, recently I switched to dell u3219q (4k), connected via the usbc cable that came with the box, temperature is around 45 to 50, sometimes bump to 60 then drop back real fast, which is reasonable for the load imo.

My spec: 16 inch base model, 5300m, i7, 16gb

Previously, I thought it was a software issue, but now I suspect there might be something with the way how the hardware works.

All temperature readings based on iStat menu.

For those experiencing the heating issue with external monitor, buying a usbc monitor might solve your concern.

my 2 cents

However, one more thing worth noting is that my gpu consumption has been sitting at 97% to 100% after connected to the 4k display, could be due to the fact that 5300m only has 4gb vram.\

Anyways, there is definitely a lot more apple can do with Catalina and the 16.

I have encountered the same issue, having my MacBook Pro 16" just for 1 week.

My specs:

i7, 16 GB, 512 GB, AMD 5300 Pro

There is a big official thread https://discussions.apple.com/thread/250878229

Any updates? Having the same problem.

Of course, all this is sad, especially if this behavior has not been observed before. The problem is, for me personally, it's hard to find an alternative to MacBook Pro 🤷‍♂️.

Hi, do you have any new information about this issue?

When connecting an external monitor in the istat program, what is the Radeon High Side parameter?

I have a DELL UltraSharp u2719dc 27 " monitor (2560×1440) and I also connect it usb-c to usb-c and mbp 16 heats up very quickly, in the istat program, the Radeon High Side option shows the value 18W!

5W for me when idle

20 w watching YouTube on safari 1080p