The usage for each processor can be monitored with PerfCpu. Not long ago we received a request to monitor the average CPU usage (for all CPUs). If Prozessor0 has a usage of 40% and Prozessor1 a usage of 80%, the check in this mode would return OK up to a threshold of 60% (average of 40 and 80). This option will be included our upcoming release 3.4.0. Use the switch --avg to change to averaged mode. Please refer to the advanced example for PerfCpu.