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. Beginning in Version 8.2-
    1, OpenVMS Integrity servers supports 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 does 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.