Can RC6 (GPU power management) status be changed during runtime?

perhaps u could take a look in cpufrequtils (if u have prerequisites). TLP also works, but not so specific.

I came here because I had the same question, and I believe the answer is no, you can't change the parameter at runtime.

Unfortunately, I don't know enough to elaborate on this, but I found this post that might be helpful.

You can, however, change the parameter temporarily at boot time if what you're trying to do is test the change before making it permanent (which is what I've been trying to do).

You can also do:

sudo modinfo i915 | grep "i915_enable_rc6"

You would see this:

    parm:           i915_enable_rc6:Enable power-saving render C-state 6. 
    Different stages can be selected via bitmask values (0 = disable; 1 = enable rc6; 
2 = enable deep rc6; 4 = enable deepest rc6).
    For example, 3 would enable rc6 and deep rc6, and 7 would enable everything.
    default: -1 (use per-chip default) (int)

I think that answers your question : )