What are CPU "C-states" and how to disable them if needed?

Solution Verified - Updated -


  • What are C-states, cstates, or C-modes?
  • How can I disable processor sleep states?
  • How to prevent the kernel to override the BIOS C-state option?
  • Is intel_idle.max_cstate=0 required to disable CPU C-states?


  • Red Hat Enterprise Linux 7
  • Red Hat Enterprise Linux 6
  • Red Hat Enterprise Linux 5

Subscriber exclusive content

A Red Hat subscription provides unlimited access to our knowledgebase, tools, and much more.

Current Customers and Partners

Log in for full access

Log In