Level 1

26 points

High GPU Power Consumption While Using External Monitor in MacBook Pro 16-inch

I know that there is a wide post about fan noise in MacBook Pro 16-inch. It's an old post, and this issue is not clearly communicated there to all users.

While I connect an external monitor and use the internal screen as well, the GPU power consumption rises to 18 Watt in idle state. It leads the CPU temperatures to rise as well.

I use iStat as my system monitor, and you can see the results:

Beyond the fairly high CPU temperatures in idle state, the problem starts to get very disturbed when I do basic operations, and naturally the CPU temperatures rise by at least 10 to 20 degrees as a result. Directly, this causes the fans to work frequently.

I hope it's a driver issue and Apple will fix it ASAP.

Interested to hear others experiences.

MacBook Pro 16", macOS 10.15

Posted on May 2, 2020 9:15 AM

Top-ranking reply

Grant Bennet-Alder

Level 10

140,327 points

Posted on May 10, 2020 10:22 AM

Under heavy loads, the fans will make noise, and that is as expected. These MacBook Pro have Amazing capabilities never seen before in a notebook format.

Several work-arounds have been proposed that tend to reduce fan activity under MODEST uses:

• using DisplayPort family interfaces (or Thunderbolt or USB-C) as opposed to heartbeat-refresh interfaces such as HDMI or DVI or Analog VGA, especially at higher than 60Hz refresh rates.

• Closed clamshell mode, which turns off the built-in display, a heartbeat-refresh display.

• disable Turbo Boost with a third-party Utility.

• applying the power adapter through the RIGHT side instead of the left.

As always, "your mileage may vary".

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22 replies

Nevroze

Level 1

8 points

May 8, 2020 12:10 AM in response to davidbenda

I think the only solution if a firmware update from Apple, that's it. We could see it as part of one of the next macOS updates, we can only hope. Maybe in 10.15.5, which is going to come soon, you never know.

Nevroze

Level 1

8 points

May 3, 2020 10:42 AM in response to davidbenda

I'll do that, the more we do it the better I guess.

dcristof

Level 1

8 points

May 4, 2020 3:17 PM in response to dcristof

BTW, configuration is 2.3 Ghz i9, 8 core, 32 GB RAM, 8 GB Radeon 5500M.

davidbenda Author

Level 1

26 points

May 7, 2020 4:40 AM in response to ToBro114

I reported it to AMD, they told me that they only supply the hardware for Apple's products, they can't do anything in order to help up.

TailsDog

Level 1

18 points

May 2, 2020 9:29 AM in response to davidbenda

I am also experiencing this problem, connecting a monitor will raise the machine temp by 20c+ when idle. When doing video calls the temp can increase significantly, something which does not happen when the monitor is not connected.

MacBook Pro (16-inch, 2019)

2.3 GHz 8-Core Intel Core i9

16 GB 2667 MHz DDR4

AMD Radeon Pro 5500M 4 GB

Intel UHD Graphics 630 1536 MB

LG 34WK95U-W

Resolution: 6720 x 2834

UI Looks like: 3360 x 1417 @ 60 Hz

Framebuffer Depth: 30-Bit Color (ARGB2101010)

Mirror: Off

Online: Yes

Connection Type: Thunderbolt/DisplayPort

Am using the same cable that came with the monitor and which was working with the previous gen MBP.

karel112

Level 1

4 points

May 2, 2020 9:55 AM in response to TailsDog

I have the same problem.

MacBook Pro (16-inch, 2019)

2,6 GHz 6-Core Intel Core i7

16 GB 2667 MHz DDR4

AMD Radeon Pro 5300M 4 GB

Intel UHD Graphics 630 1536 MB

Samsung S32D850T

Resolution: 2560x1440 60 Hz

Connection Type: Thunderbolt/DisplayPort

I also tried the official Apple HDMI adapter with the same result.

wegster

Level 1

8 points

May 3, 2020 11:32 AM in response to Nevroze

Same issue.

MBP 16 - 32GB RAM, 2TB SSD, 8GB AMD.

Numerous cables, with and without a dock - zero difference - always 18W+ with a single LG external display, so will heat soak sooner. 5W in clamshell mode.

It took Apple YEARS before they built a system I was willing to replace my higher end 2015 MBP with, and now this. This is not appropriate for a 'highest end MacBook PRO.'

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High GPU Power Consumption While Using External Monitor in MacBook Pro 16-inch