While working on some alerting and metric collection about our infrastructure at Bitmovin I wanted to test out if the alerts I configured are actually triggered when a server experiences high CPU load.
I came across this beautiful Stackoverflow Answer that did exactly what I needed:
seq 3 | xargs -P0 -n1 md5sum /dev/zero
This command will saturate 3 cores with 100% user load until you cancel the command with CRTL+C.