Firmware Test Suite - cstates test

The cstates test checks all the C-States of all CPUs on a system. The test will:

  • Check that all CPUs have the same number of C-States.
  • Attempt to transition each CPU to all the different C-States. Sometimes this is not possible and this is not a fault of the system and hence is not marked as a failure mode.

Note that this test will exercise each CPU one by one and hence requires an unloaded system to work correctly. The test can take several minutes of one has many CPUs.


fwts cstates - 

..runs the test on your machine and dumps the output to stdout.

Explanation of test results

Certain test results may require a little more explanation. This section will try and give some context to specific test failures.

Error ID



A CPU is expected to have a C state but doesn't. This means C-State configuration is inconsistent across the CPUs.


/sys is not mounted, and hence the test cannot access the relevant /sys entries to examine C state settings on each CPU.

FirmwareTestSuite/Reference/cstates (last edited 2016-01-11 07:25:29 by anthonywong)