Previous blogs on power management and a host of other power management resources can be found in List of Useful Power and Power Management Articles, Blogs and References.
WHAT AND WHY DO WE WANT TO CONFIGURE IT
There are several reasons why you might want to configure your power management in different ways. For example, you may want to disable turbo due to the sensitivity of your application to OS jitter. The table below lists some of the reasons you might want to change a power setting.
Power setting change
PC3 enable / disable
Examples similar to that of PC6 enable/disable with the exception of PCI events. Latency dramatically increases once you drop into PC3 since the part of the coprocessor power management module that is on the host needs to initiate an exit from PC3 back to C0.
P1 enable / disable
CO6 enable / disable
In a smaller cluster, you may want to experiment with enabling versus disabling turbo. Enabling or disabling various power management states may give you some performance gain for specific workloads.
If you are designing a large cluster, you may want to disable turbo because it may increase the headroom your thermal extraction system (e.g. air conditioning) needs to support the coprocessor. This can be the case even if the average meets your specifications.
NEXT: Intel Xeon Phi coprocessor Power Management Configuration: Using the micsmc GUI
Kidd, Taylor (2013, October) List of Useful Power and Power Management Articles, Blogs and References, revision 1.0, Intel® Developer Zone website, Intel® Corporation, http://software.intel.com/en-us/articles/list-of-useful-power-and-power-management-articles-blogs-and-references