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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

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Question marked as Top-ranking reply

Posted on Mar 25, 2021 8:51 AM

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.

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6 replies

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 .

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

High CPU utilization by kernel_task process when external monitor plugged in

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