C-states are the idle state policies that govern an x86 system - i.e. states that shut down parts of the microprocessor when cores are not used. Modern x86 microprocessors have several C-states representing an increasingly larger part of the processor that's being shut down. Additionally because x86 MPUs are also exclusively multi-core, most recent microarchitectures include two C-states: core-based C-states called CC-states and a package-based C-states called PC-states.

This article is still a stub and needs your attention. You can help improve this article by editing this page and adding the missing information.