Kernel_Task running 500%?

I have a Mid 2015 MacBook Pro 2.5 GHz i7 with 16 GB. Recently it began slowing dramatically. I restalled High Sierra from scratch. No matter what I do, I can’t get it to run normally. My CPU Temp is normal but my Kernel Task seems out of control.

I also resent the smc controller and PRAM. Any thoughts?

Was hoping to get through to the fall to replace with hopefully the next iteration.


This usually happens when either something is out of control, or when your Mac is too hot and trying to cool itself down. Were any heavy duty apps running at that time?

Can I ask what is being measured here? I’m sure it is probably obvious to most people that ‘over 500%’ is significantly greater than 100%, or ‘everything’, so I’m just a bit lost as to what is actually being shown by this processes list. It can’t be something proportional or being measured against a snapshot, so I’m left wondering what this is.

Also don’t forget you’re shown 4x100 at least, as it could show all 4 cores, so something is still strange (at 125% minimum), but less weird than 500% at 1 core

There are almost no apps running, Dropbox is about it. Fan is running at full speed processor temp seems normal, but fan doesn’t stop and the computer runs very slow. Delayed cursor movements, safari load time is about a min… and so forth.

I am not versed enough to understand what it means. But fan running full speed 100% of time and the lethargic system speed, Takes about a minute to open safari now and most cursor movements are delayed, tell me something is wrong, just don’t know what it is. I have had zero hardware issues, most of the time the machine sits on a table so I would be surprised if after all this time something failed or is failing hardware wise.

Can you share some activity monitor screenshots?
Sortd cpu and memory load high-low?

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You could boot from a macOS install usb and let the machine sit for a few minutes (or however long it takes the symptom to appear). If it still happens, it’s probably hardware, if not, it’s software.

Great idea, appreciate it