On Integrity servers, a CPU can be placed in "low-power mode"
    when it is idle. This minimizes power consumption, thereby
    reducing energy costs for the system. OpenVMS Integrity servers
    support this feature based on the settings of two system
    parameters: CPU_POWER_MGMT and CPU_POWER_THRSH.

    A value of 1 for CPU_POWER_MGMT means ON (the default); a value
    of 0 means OFF. Whenever the CPU_POWER_THRSH parameter value is
    exceeded, the operating system places an Integrity processor in
    low-power mode if it is idle. OpenVMS Integrity servers do this
    only if CPU_POWER_MGMT is on. A CPU returns to normal power when
    it receives an interrupt.

    CPU_POWER_MGMT is a DYNAMIC parameter.