kernel_task CPU usage with external display

Connecting an external display to some MacBook Pro models via Thunderbolt may cause this issue. I don't know of a fix, other than to disconnect the display.

This worked for me

I have two external monitors connected to MacBook Pro - experiencing similar HIGH kernel task activty

In my case it appears to be a heat issue & high computer fan activity

Raised the MacBook Pro off the surface (placed small objects underneath & have a large room fan blowing over the MacBook

Solved my HIGH kernel task activity

Exterenl monitors or monitor + heat + computer fan activity = High Kernel task activity 🙂

Try cooling procedures

I'm running a Mid 2012 MacBook Pro Retina...

Have been having this problem with the monitors at home where I have 2 Thunderbolt Displays.

It appears, at the moment that the problem is the MagSafe 2 power adapter.

I tried it on BOTH displays so far and as soon as it's plugged in and giving power, to the laptop through the adapter it takes about 3 minutes and the Kernel_Task process spikes. So far I have been running it for about 20 minutes on the laptops power adapter and it seems to be fine. Haven't had it spike the CPU at all.

One thing I did notice, is that I kept having to bump the power adapter (Thunderbolt with MagSage 2 Adapter) to get it to power the laptop. That's out I found it. But when I took the power adapter off, it was VERY warm.

Try it, it might be the problem.

ok, one other thing you should try is to go get the latest Combo updater for the version of the OS you are running.

Here is the link to the 10.11.4 update.

Download OS X El Capitan 10.11.4 Combo Update

Applying this also seemed to have cleaned up a lot of issues on my machine as well. I am still testing out both solutions. I did get it to start spiking again last night after 4 hours on the normal adapter, But it hasn't happened since I applied the combo update... Yet.

I can confirm that this bug is still at large