The ISPU has two clock settings available: 5 MHz and 10 MHz, which can be selected by setting the ISPU_CLK_SEL bit in the CTRL10_C (19h) register. By default, 5 MHz is set and that is what you should normally use. Only if your algorithm is running too slow at 5 MHz, then you should switch to 10 MHz. You should only do it in that case because if the sensor is set in accelerometer-only mode (gyroscope off), switching to 10 MHz will slightly increase the power consumption. If the gyroscope is on, in terms of average power consumption it is equivalent to use 5 MHz and 10 MHz. Please refer to the application note of the ISM330IS for further details.
