Cool read on new p-states with Intel's Skylake
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http://www.anandtech.com/show/9751/examining-intel-skylake-speed-shift-more-responsive-processors
Summary: The CPU controls frequency and voltage instead of the OS. The CPU can change frequency and voltage in as little as 1 ms(instead of 30+ ms, but about 3x faster is the norm), allowing for better response to bursts of work. Nearly identical power usage, but better response to sudden load when the CPU is idle.