Ahwell, Graphs lie. This one shows 23% Average CPU usage, 36% highest. But CPU Temp 85°C?
Nope, it's not a broken CPU fan, that thing works nicely, I can hear it...
It is only one value of the CPU valuesthis graph seems to take in account, the others are ignored. (user/system/nice/wait/..., more than one, anyone?)
System was busy on reading LOTS of data from 8xspinning rust and writing into the cache M2 SSDs and off to the network.