MacBook Pro kernel_task goes to 800% CPU at higher resolutions when connected to external monitor

This computer was built with a ninth generation 14nm processor. The only way to meet the target performance was to make it a six or eight core processor. This processor generates an enormous burst of heat when it does Turbo Boost, and there is only one cooling rail shared by both the CPU and GPU. So getting Either side too hot ramps up the fans.

This processor was supposed to be an eleventh-generation 7nm processor, but intel is three years late, and is only starting to ship its tenth generation 10nm processors now.

Apple DID redesign the cooling system for this specific Mac. New, high-efficiency fans are used. But for some uses, that is still not enough.

NB>> Some of the best advice is to install Turbo Boost Switcher and turn off CPU Turbo Boost. This reduces the huge sudden overheating brought on by Turbo Boost, that simply does not translate into real-world performance gains.

How to fix your 16-in MacBook Pro (Don’t return it!)

https://www.youtube.com/watch?v=EkmdHVfk4XE

Hello there nvijay78,

We understand your Mac's fans are speeding up and kernel_task is also using up additional resources while using an external display. Let's take a closer look as we do our best to provide some additional insight.

To get started, we first want to make sure that your Mac is working within normal operating conditions. What is the ambient temperature where you're currently using your Mac? Is it on a flat surface allowing open air to the vents etc? Keep your Mac notebook within acceptable operating temperatures

Next, does the same thing keep happening after a restart, or while connected to a different kind of display or monitor? We just want to rule out an issue with with this particular one.

From here, we can focus on some of the systems that control fans and other system functions. The first step is to reset what's called the SMC: How to reset the SMC of your Mac

After completing those steps, we can also reset the NVRAM to help save time: Reset NVRAM or PRAM on your Mac

Then you can test things out after completing both of these steps.

We hope this helps!

Take care.

Changing away from HDMI to DisplayPort family (or to ThunderBolt-display or USB-C display) will reduce the Voltages and slightly reduce the heat generated. It is a good thing to do, but it may not be enough to solve this issue by itself.