High system CPU usage

I have a mid-2012 MacBook Pro (10.12.6, 2.5GHz intel core i5, 16GB RAM, 500GB SSD) which despite its age had been running remarkably well - starting up/shutting down within 10 seconds, running cpu intensive software etc.

After not using it for a couple of months I’ve booted it up and it is now unusably slow. Activity monitor is reporting 80-85% system CPU usage even with no apps open.

What could be causing this?

MacBook Pro 13″, macOS 10.12

Posted on Mar 5, 2021 7:40 PM

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2 replies

Mar 7, 2021 5:48 PM in response to genuinelulabelle

Eventually figured out it was the seemingly common kernel_task bug. Originally it wasn’t showing up in activity monitor for some reason but now I can see that that is where all the CPU power is going.

Mar 5, 2021 7:40 PM in response to genuinelulabelle

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High system CPU usage

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