SW Power Cap question


Using a Titan X (Pascal) for a deep learning application I notice in nvidia-smi the following:

Performance State               : P2
    Clocks Throttle Reasons
        Idle                        : Not Active
        Applications Clocks Setting : Not Active
        SW Power Cap                : Active
        HW Slowdown                 : Not Active
        Sync Boost                  : Not Active
        Unknown                     : Not Active

However the power utilised is way below the max:

Power Readings
        Power Management            : Supported
        Power Draw                  : 81.54 W
        Power Limit                 : 299.00 W
        Default Power Limit         : 250.00 W
        Enforced Power Limit        : 299.00 W
        Min Power Limit             : 125.00 W
        Max Power Limit             : 300.00 W

Temperature is also low:

        GPU Current Temp            : 65 C

Could anybody explain why the clocks are throttled and the performance state is ‘only’ P2?

This is under Ubuntu 17.04 driver 375.66

Thank you!