kernel_task takes up 500% of my CPU when plugging in external monitor
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 mode
- Disabled Spotlight indexing for specific types of content and also added folders like “/System” in the Privacy settings
- Reset 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 HDD
- Using plain HDMI cable into the HDMI cable port
- Taking MBP apart and cleaning any potential dust
Has anyone had similar experience with this issue and how to address it?
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
Hi - I have the same problem. Have a MacBook Pro mid 2015. It works fine with no external monitor connected. When external monitor is connected, kernel_task often runs to 500 % CPU (how can that be?). The whole Mac slows down to an almost standstill, and the fans sound like an early WWII fighter plane. Have you had much luck finding out what solves this? JP
Try this: Unplug your monitor from the AC outlet now plug in the display only into your Mac. Does that work OK then?
Guys I'm also facing the same issue with my Macbook Pro Mid 2015. Could you please let me know if you guys were able to find the solution for this before.
Vishal Kalia さんによる
@Vishal Kalia - The issue is a damaged thunderbolt port chip on the logic board.
@danj hiya Dan, not sure if it is the Thunderbolt, but I still haven’t tested it (lack equipment and ability). I have an additional issue where iPad or iPhone plugged in via USB can sustain a connection (the trust dialog opens and closes sporadically ). There’s definitely something wrong hardware wise and I fear it’s related to the motherboard.
@jonpp @Vishal Kalia do you have the same issue I have with USB as well?
Matt Scheurich さんによる