Why do numbers in Activity Monitor never add up?
Solution 1:
The numbers in the top section are 'per core' [including virtual Hyperthreading cores].
Those at the bottom are 'the whole Mac'
So, depending on how many cores your Mac has, 100% in the top section might be 4, 8 or 12 times the total figures. That's how you can on occasion see huge numbers, like kernel_task trying to cool the Mac by running at 500% - that's 5 entire cores all being marked as busy.
You might guess that would be a 4-core Mac, with hyperthreading.
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