Check_mk adopts a new a approach for collecting data from operating systems and network components. It obsoletes NRPE, check_by_ssh, NSClient and check_snmp. It has many benefits, the most important of which are:

* Significant reduction of CPU usage on the Nagios host.
* Automatic inventory of items to be checked on hosts.

The larger your Nagios installation is, the more important get these points. In fact check_mk enables you to implement a monitoring environment exceeding 20.000 checks/min on the first hand.