Chosen Solution

Since I plugged in an external monitor (via thunderbolt) my kernel_task ramps up to 500% and can’t do much on my MBP. I researched a lot online and did the following: Disabled Energy Saver - Automatic Graphics Switching on both Battery and Power Adapter modeDisabled Spotlight indexing for specific types of content and also added folders like “/System” in the Privacy settingsReset the System Management Controller (SMC)Performed the Apple Diagnostics test (ADT - some older websites called it the Apple Hardware Test - AHT) and had no issues come from that.I also use Google Drive’s “Backup and Sync” and do lots of web development with node_modules folders, that can have 10s of thousands of small files which I think results in CPU churn. I’ve disabled it now.Shut down the computer and turned it back on. Still get same issues with the external monitor. Now with no external monitor plugged in, every once and a while the kernel_task rises up to 300% and sometimes rarely to 500%. I’m curious if it is a software thing or a hardware thing. To me it seems more like a software thing. I use VS Code for programming which can have a lot of background tasks, same with using node/npm which can probably be doing lots in the background. I also run iStat v6.30, and sadly I have only 21 GB of free space on my HDD (out of 500 GB…). Often I also have Slack open, and I know that’s a web app using Electron to run as a desktop application, which can be notorious for performance. Often the fans can run high as well. I often suspect it is either due to the VS Code/npm/node/Slack thing, or kernel_task, or maybe something else I’m unaware about. When checking memory usage via iStat, I can see that kernel_task is using 1.61 GB (oof, Firefox is using 6.36 GB). Things I haven’t tried yet: Cleaning out more free space from HDDUsing plain HDMI cable into the HDMI cable portTaking MBP apart and cleaning any potential dust Has anyone had similar experience with this issue and how to address it? OS: 10.13.6 Processor: 2.5 GHz Intel Core i7 Memory: 16 GB 1600 MHz DDR3 Graphics: AMD Radeon R9 M370X 2048 MB, Intel Iris Pro 1536 MB

What helped me to solve the probem is to disable completely the Bridge Thunderbolt settings in the network configurations. I had issues for more than 4 months, disabling it brought back my mac pro 2015 to a new life.

I recall that the kernel_task problem is actually a feature to protect the computer, I believe from overheating but possibly other things (not confirmed). Cleaning out the dust in the computer/fans can help. I also found some luck by moving my external monitor to the second thunderbolt port. Possibly the one it was using is defective? Just to test, I plugged in another thunderbolt peripheral into the suspect port and the kernel_task problem did recur. So maybe that is the main problem, a bad thunderbolt port. My setup is also mid-2015 MBP 15” and this occurs primarily if I use both the screen on my MBP at the same time as the external display (Dell 24” 2K) (i.e. so I have two screens). Peace to all.

The Thunderbolt to HDMI adapter you are using may have damaged your Thunderbolt port. Also check your AC power outlets and the monitor/TV is plugged in to the same outlet and the polarized plug is plugged in correctly. Its possible you zapped your port by cross-wired AC between your system and display so the ground side was hot! Get a outlet checker to check the outlets.

Folks this is an image of my fans before I had them cleaned.

I faced the very same issue that you guys are facing and based on input from another forum decided to get my 2016 MPB fans cleaned out. This made an immediate impact where when I connected my external display to the MBP.pre-cleaning, it would overheat causing the fans to spin at 6000 rpm or thereabout and the kernel_task would eat up 500%-900% of the CPU rending the system unusable. This simple cleanup of the fans has allowed me to connect the monitor with no kernel panic anymore and even though the fans run around 5000 rpm now the CPU and GPU are running around 10 degrees cooler now.

Resetting SMC helped fix me! Shut down MacHold. CTRL+OPTION+SHIFT+POWER button for 10 secondsRestart Mac

@danj and @mattscheurich I’m also facing the issue. I have a 2K display attached to: MBP mid 2015Processor: 2.5 GHz Intel Core i7Memory: 16 GB 1600 MHz DDR3Graphics: AMD Radeon R9 M370X 2048 MB, Intel Iris Pro 1536 MBThe CPU goes bonkers and kernel_task remains at +400%. Unplugging the Dell 2K display immediately settles it down. I’m using plain HDMI cable for the display, it’s not a thunderbolt. I’m not sure how a damaged Thunderbolt chip can be a cause here because I’m using HDMI?