High CPU utilization by kernel_task process when external monitor plugged in

Question

Level 1

9 points

High CPU utilization by kernel_task process when external monitor plugged in

I have a MacBook Pro 16" 2019 i9 Processor with 32 Gig Ram.

Whenever i connect an external monitor using HDMI (Dell Monitor) a process called kernel_task starts taking very high CPU (says 1000%) and all the applications become very slow.

As soon as I unplug the monitor the CPU utilisation of kernel_task reduces and everything is normal.

Because of this i am not able to use the external monitor. The issue was in Catalina OS and also in Big Sur. Seems to be a very old issue.

Is there a solution/workaround for this?

Posted on Mar 25, 2021 7:45 AM

Reply

Answer 1

Best reply

BobHarris

Level 9

53,339 points

Mar 25, 2021 8:51 AM in response to nikunjrathi

https://support.apple.com/en-gb/HT207359

The kernel_task may be faking high CPU while putting the CPU chip into a low power idle mode, giving the Mac a chance to cool off.

Reply

Answer 2

Mar 25, 2021 7:50 AM in response to nikunjrathi

Try a different I/O connection path to that unspecified Dell monitor, replacing the use of HDMI here.

See if that works better.

That looping kernel task is reportedly a means to thermally throttle to prevent damage.

Reply

Answer 3

pkpzone

Level 1

4 points

Apr 11, 2021 2:27 PM in response to nikunjrathi

I have also the same issue on my MacBook Pro 2019 15 inc model. Nothing seems to be working. It's not an heating issue, Whenever we connect the external monitor , Graphics switch to dedicated (High performance graphics ) snd this problem starts. This bug present in most of the Apple MacBook pro.

I have created case also with Apple as my laptop is under warranty but Apple also unable to fix this issue, they have told me to format the machine , I have done that but problem is still same. No FIX TILL NOW.

So much frustrated of using MacBook .

Reply

Answer 4

nikunjrathi Author

Level 1

9 points

Apr 11, 2021 9:08 PM in response to pkpzone

That is true. It has become very difficult to use this beast of a machine. My external monitor is rendered useless. I code regularly and i prefer using a big monitor but cannot use it because of this issue.

There has to be come workaround.

May be i will try with a USB Type C connection to the monitor. Currently i am using HDMI to connect to the monitor

Reply

Answer 5

BobHarris

Level 9

53,339 points

Apr 12, 2021 5:25 PM in response to nikunjrathi

Does your monitor have a different connection port (HDMI vs DisplayPort vs USB-C vs DVI vs VGA). Can you try a different connection method?

Just for fun, if your Mac is using USB-C ports, can you rotate which USB-C port you plug into.

All of this is elimination testing.

Reply

Answer 6

Apr 11, 2021 2:37 PM in response to pkpzone

That’s heating.

Your external monitor is taxing your graphics interface.

Switch your display connect path, as a potential remediation.

Reply

High CPU utilization by kernel_task process when external monitor plugged in

Similar questions