A future article on Phoronix.com by Michael Larabel looking at the latest Intel RC6 support as of 11 February. Difference between test runs is rebooting the kernel with i915.i915_enable_rc6= to values of 0, 1, 3, 5, and 7.
Compare your own system(s) to this result file with the Phoronix Test Suite by running the command: phoronix-test-suite benchmark 1202110-BY-INTELSAND13