What I read

CPU Utilization is Wrong

brendangregg.com / 21 May 2017

CPU utilization has become a deeply misleading metric: it includes cycles waiting on main memory, which can dominate modern workloads. You can figure out what %CPU really means by using additional metrics, including instructions per cycle (IPC). An IPC < 1.0 likely means memory bound, and an IPC > 1.0 likely means instruction bound.