High CPU usage kernel_task with 2 monitors

I see so many same issue on this topic and it seems there is really no solution as I have tried every single possible things recommended and suggested in the internet..! I think this is a design flaw either software/maybe also hardware by Apple on this models. Apple really should give their position and fix on this..!

Unfortunately same issue here :(

I was having this issue and solved it by adjusting the refresh rate of the external monitor.

1. Go to System Preferences>Displays
2. Click Display Settings...
3. Select the external display

In my case it was originally set to 27 hertz. The only other option was 30 hertz. A soon as I switched to 30, the CPU usage dropped. I wouldn't have thought that increasing the refresh rate would ease the CPU usage, but it did.

2019 16" Macbook Pro

I had a same problem for a long time.

I tried everything to fix this issue but no luck.

Finally, I've found a way to fix it.

Just open up the bottom cover and clean the fans and heat-sink.

Like many others in the thread, after opening the back cover, disconnecting the battery and cleaning out the dust with brushes and compressed air, the high cpu usage when using an external monitor seems to have decreased.

Helpful youtube videos:

https://www.youtube.com/watch?v=KyMjUCB-hhU : this was way more difficult than i expected. I felt i should have just gone to an apple store when doing this

https://www.youtube.com/watch?v=tBrKXhkfnAE : this video goes into removing a lot more things than just the battery to apply thermal paste, i didn't do any of that - can be risky to remove and replace a lot of parts. in my case my macbook didn't turn on after i put the back cover on initially and i was freaking out a bit. But it turned out i didn't connect the battery wires properly, i didn't need to lift the 2 small plastic clips for removing the black wire with the S pattern initially, but that lead to the ends not being connected properly when i put it back. the lesson was to follow the video very closely.

Tools i used:

Brushes: https://www.amazon.com/dp/B074LZ649V?psc=1&ref=ppx_yo2ov_dt_b_product_details

Screwdriver: https://www.amazon.com/dp/B07TXFYP5G?psc=1&ref=ppx_yo2ov_dt_b_product_details

FIX to drop kernel_task CPU load when using a 2nd monitor in Monterey:

System Preferences -> Battery -> Power Adapter -> DISABLE/UNCHECK "Automatic graphics switching"

I have tried a lot of things, but this one seems to do the trick while using a 2nd monitor. Besides, you can always re-enable it when you are "on the go", i.e. on battery.

My laptop is under warranty. 2020 i5 16GB. I took it to the shop before reading this thread and found that the error was coming from my external monitors. I was told there was no problem and that the fans were clean, so it's not a solution for me.

With the pre-Monterey version it didn't happen to me. It's a pity. I would say that in version 12.6 they have patched something because I don't get crashes, although it does slow down the computer, with the kernel_task going up to 30-40% and the CPU_speed_limit going down to 50..... It only happens when I make video calls. Without connecting monitors I don't have any problems. I have several colleagues in the company who also have this problem, and another who does not with the same laptop model.

I connect the monitors via HDMI to a hub that connects to the laptop via USB-C. Maybe a different hub would help?

I find it very serious that this is happening. Very bad done by Apple for not providing solutions in my humble opinion.

I have the same problem with my macbook pro 2017, out of support. I've tried almost all recommendations in this forum and others without luck. My external monitor is a Dell and the problems started when I updated to Monterrey. Recently I updated to Ventura 13.0 and the problem remains. Has anyone been able to fix it or a workaround?

Still suffering from this, as I have been for the last two versions of MacOS. Prior to Monterey, no problem, since then, hideous degradation when using my 27" Apple T-Bolt display, which I prefer to do actual work on. I got on chat with an Apple support tech, he thought it should go away with Ventura, but no dice, sadly. It's making my machine unusable, for all purposes, and it's an i9 with 32GB! Doesn't matter how many cycles you can pull, if the OS eats them. I've loved my Mac gear for the last 15 years, but this is shaking my faith.

Has anyone tried connecting to your external display via HDMI only? (I don't have a dongle to try it)

SOLVED I took my 2018 i9 (32GB) to the Genius Bar. Internally it was really badly blocked up with dust. Air couldn't get in, and air couldn't get out. Blowing all the dust out has made my machine 'breath' properly again. The kernel_task issue disappeared immediately after doing this.

I have same issue with 2015 retina MBP. I have a 27” Thunderbolt Display connected and plagued by kernel task eating up CPU. I’ve tried resetting NVRAM and SMC. I’ve had a new battery installed, had fans and vents cleaned out, new thermal paste applied. And STILL I get the issue. The laptop works just fine when not connected to the display. It’s clearly a problem with the display but can’t seem to resolve the problem. For an expensive display it’s really unacceptable that I can’t even use it with my Apple computer. Don’t know if anyone has any other ideas???

MBP 16 i7 2019 here:

My equipment:

• 4k @60hz samsung monitor (displayport)
• 2k @120hz asus monitor (usb-c)
• Caldigit ts4 thunderbolt dock (Some of devices attached to it, like elgato streamdeck mini, 1080 webcam, hyperx quadcast mic, keychron k2 keyboard)
• Type of sh1t i run: docker desktop, tons of chrome instances, minikube, slack, teams, terminal, intellij

Observations:

• When using without nothing attached, temperatures where consistently fine (45C - 50C)
• When connecting my MBP to the caldigit hub (using the thunderbolt cable) temps immediately increased to 65C-70C (both monitors working)
• At some random moment, kernel_task process rises to 700% cpu usage, turning the computer unusable. (temps go from 65C to 95C)
• When leaving the computer to sleep and wake up, both monitors start to make strange on/off glitching for a minute or so

Things that seem to help:

• Connect the main thunderbolt cable on the right side of the computer (for some reason left side tends to release more heat)
• Increase the display scaling (so text gets bigger) on the main monitor (in my case the 4k monitor) and reduce the resolution. Both settings are intended to give a chance to the amd gpu to cope with the demand.
• Forget about a third monitor, just use one external.

Things that didn't work (in my case):

• nvram/smc reset

Things i would like to give a try:

• Removing dust from fans - I guarantee you, dust is a fk devil.
• Re-applying thermal paste (many people report this step reduces temps by 10C)

Disclaimer: Don't you ever try to open that machine unless you own the proper tools and are prepared for the worst case scenario (buying a new laptop)

Most likely culprit:

• AMD GPU, dust and old thermal paste

This happened to me when I updated my OS. I'm no longer able to use my second LG monitor because Kernel_task goes all the way to 1000% and the computer becomes non responsive. It is a bummer, because I really like my second monitor. I hope they fix this problem for all of us. I'm afraid to get another monitor just to find out that the issue persists.

And the long silence from Apple continues. I'm down to using just the notebook, no externals at all, when I normally run two big external monitors. HELLO, APPLE?????