High CPU usage kernel_task with 2 monitors

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?????

Charming! I upgraded to 13.3.1, and now it happens WITHOUT an external monitor connected. I've reset the SMC and PRAM, to no avail. Hello, Apple?????

Same issue here. It puzzled me for a couple of months now.

MacBook Pro/i9/32G/Ventura 13.3.1

Initially I thought my dock station is the issue, I moved everything and directly plugin all displays to USB C. But it still happens. CPU usage of kernel_task raise to 700-800% level and fan blows like crazy.

I tried the nvram/smc reset trick and it seems too be working fine now. I will report if it comes back.

I've got high cpu usage (~90% constantly) after upgrading from Ventura 13.2.1 to 13.3. Setup:

MBP-Pro 2019
1x 5120x1440
2x 2560x1440
1x 1600x1000
Everything used to work fine till the upgrade with this setup.

But in my case the CPU usage caused by Google Chrome Helper (Renderer) processes. It's enough to open 1-2 instances of chrome and surf the internet and it happens. Closing chrome (quitting) helps after 1-2 mins and the CPU goes low. The weirdest thing that after reinstalling my MBP completely to 13.2.1 didn't solve the problem. And I have another MBP running 13.2.1 where there is no such issue occurs on this setup.

At work I have built-in Retina + 2x 2560x1440 and everything is fine. No issues.

And the parade of MacOS updates with NO fix for this long-standing issue continues. 13.5.1 acts perhaps even worse, spinning out my machine as soon as I connect one monitor. HELLOOOOOOOO, APPLE???????

I connect HP monitor thru VGA cable to micro USB port and kernel_task spikes to 1300% ! I tried all resets mentioned but it doesn't solve the problem. Mine is a MBP 2.6 GHz 6-Core Intel Core i7 any help ? I cannot use external monitor at all

Any help APPLE

OMFG! I bought two brand new LG 32" USB C monitors. Great monitors, and for the first two or three days using them, no instances of this. But now, it's BACK, in force. I've reset SMC and NVRAM multiple times, to no avail. If I plug one or both of them in, immediate spin cycle. HELLO, APPLE????? What the hell, guys?

And the update to Sonoma 14.1 makes no difference. Apple, can we PLEASE get your attention here? This makes my sweet little MBP into a brick, for all purposes.

So, I finally got an answer. In my case, the battery was swelling, and my fans were clogged to a degree. Had the battery replaced, the machine cleaned out, and the issue has disappeared entirely.

hi, I had similar issue, I resolved it removing dust from fan's also have added new thermal paste for processor and video card... in my case macbook fans was fully of dust and thermal paste was dried...

Right guys. I'm here to possibly make your day!!

This may sound like an advert for the developer (well it sort of is) but if my initial testing works out which it looks like it will, this has saved me from upgrading from a perfectly great laptop albeit the usual fan issue we all know and love.

Mine is an i7 2015 Macbook Pro 15 inch, 16gb, 1TB, bought new by myself. However after many years, I was just about to sell on eBay cheap and buy a Macbook Air M1 because guess what it doesn't have to spoil your productive work day???

I've searched and tried all the usual !@££$%$%^ that Apple tells us with SMC, clean fans etc etc. Get this, Apple even replaced the motherboard near the end of its 3yr care support a few years back when they reckoned one of the temp sensors was playing up. Can't prove that but it didn't fix the fan issue anyway.

No idea how but I literally stumbled on this 30 minutes ago - https://www.reddit.com/r/macbookpro/comments/jiy3n8/macbook_pro_mid_2015_fan_noise/

Has anyway plugged in an external monitor for the fans to scream like a banshee until removed? 8 hour productive day ruined by T.C. refusing to give a $$$$$$ to his users? Well no more for me, thank you sir.

The app disables Intel Turbo Boost in short. You may lose some performance, haven't tested long enough to be 100% but I'm a heavy Chrome user for work. 3-4 profiles usually loaded with a bunch of tabs, but plugging my monitor in, running those and then loading Gimp to stress it, silence was golden. It has the usual app functionality so can turn off and make the babies burn up again. From what I can tell from my (as you can probably tell giddy testing) the fans will come on if needed, but as the Intel part is not boosting, the fans aren't being required as much.

Anyway if you try and it works, consider purchasing the pro version for the developer. I will once I have.

Please can I really stress to the moderators of the forums, this is a real post and not an advert to purchase a 3rd party tool. I just hope this does fix the issue and helps others. If it does guys, tell the world that these old Macbooks are still worth using. No need to give back to Apple just yet to recycle them.

Why is this an ongoing issue?!? I'm having the same problem and I've does EVERYTHING on this post multiple times. Why can't Apple fix this for good? I've reset NVRAM and SMC so many times I forgot how many, I've tried plugging power into the right side (which would be ridiculous issue), different resolutions, including all the 'low resolution' and all to default, and I've scanned for any viruses or malware... not to mention I'm fully patched. PLEASE FIX THIS Fn ISSUE FOR GOOD! I've see years of posts!

Just clean your MacBook fans, i already resolve with this. My kernel_task over 1000% down to 4%

Same issue here. The only plug that didn't generate any issue was USC-C to USB-C between CalDigit 3 dock and monitor (Macbook PRO 2019 Intel + BENK 32` 4K EW3270U) Other plugs , Display port to display port or USB-C to HDMI caused CPU overload. Dock is connected to Mac via thunderbolt 3. I agree with those who think it's a disgrace for Apple. I paid €4,700 for my machine.

Year, end of 2024 and we already have this problem :) Is there anyone to help us from apple supports? When I plug in 1 external monitor via type-c adapter (I used 3 different devices, and same result) cpu usage suddenly up to 70-80% (kernel_task) we don't know detail which process increase in kernel?

I remember that I used 2 monitor on type-c adapters and before there is no problem. We need your help Apple Inc, we have problem with your device so please support us.

I have MacBook Pro 16-inch, 2019 2.6 GHz, 6-Core Inter Core i7 Intel UHD Graphics 630 1536 MB 16 GB 2667 MHz DDR4 OS, Sequoia 15.2

Hi, guys again. I found the problem via this support information why kernel_task up to high? One of the functions of kernel_task is to help manage CPU temperature by making the CPU less available to processes that are using it intensely.

https://support.apple.com/en-us/102172

Then I think it's about my MacBook temp. and open it to clean. I noticed that there was a lot of dust, which was hindering the fan from working and cooling. After clean now everything looks like ok if its not about software I mean MacOS, think about the hardware cleaning.

If you think its about operating system;

1- Take backup via Time Machine (to return your backup if any issues), 2- Run repair disk with Disk Utility, 3- Reinstall MacOs.

Saw this thread. Normally run 3 monitors in clamshell mode. Have experienced this issue on and off but could not trace it. I have used Turbo boost (mostly on, sometimes off) Problem with high kernel_task would manifest and could not pinpoint. Restart always fixed

My 3 monitor setup: Main 4k LG (usb-c for power + monitor) Left 2560p 27" monoprice (usb-c to hdmi cable) Right 1080p 24" crap Acer ((usb-c to hdmi via hub)

I rearranged my set-up recently and ran into max kernel_task. It would repeatedly manifest when I opened a Safari window in TradingView. Only when I completely closed the window in TradingView, kernel_task would drop to normal.

A previous post mentioned turbo boost as a fix. I noticed I had turbo boost toggled to OFF. I turned Turbo boost ON and the kernel_task problem went away after repeating test going to tradingView

At this point, I believe the kernel_task issue is solved by using Turbo boost The other suggestion is to use the right side ports to power and run the 4k monitor

Highly recommend ...! purchasing SwitcResX to match resolutions across 3 monitors

Current 3 monitors resolutions (all 60 hz)

Main 4k LG ---> set at mid res = 3008 x1692

Left 2560p 27" monoprice ---> = 3008 x1692

Right 1080p 24" Acer ---> = 3008 x1692

SwitcResX does a fantastic job rendering text, making it legible

Also recommend turning off: (as recommended in one of the posts above) System Preferences -> Battery -> Power Adapter -> DISABLE/UNCHECK "Automatic graphics switching"

MacBook Pro (15-inch, 2018) 2.9 GHz 6-Core Intel Core i9 Radeon Pro 560X 4 GB Monterey 12.7.3

Will post if encounter issues again, but definitely Turbo boost solved my issues right away when Turbo boost was OFF

Hope this helps someone still using an intel MacBook that can easily run 3 monitors gracefully (including a 4th when not in clamshell mode)

Ros