R720 performance profiles

I have an R720 with 2x2680v2 procs.  2.9.0 BIOS, 2.65.65 iDRAC.

I have a question relating to the setting of the performance profiles.   

When I set the performance profile to System DBPM (DAPC) my workload consumes 150 watts of power and the system is at 20% load.

When I set the performance profile to OS DBPM my workload consumes 200 watts of power and the system is at 10% load.

My question is, since there's obviously spare capacity, the logical thing to do would be to set the system profile to System DBPM (DAPC) to save power.  

The difference between these two levels seems to be the processor frequency.

My question is, if the workload increases, will the system dynamically adjust the processor frequency as needed without having to go back into the BIOS and adjust it manually?

If so, what are the thresholds of system load for the BIOS to increase CPU frequency?