Comment 131 for bug 640100

I am not a hardware person, but this is what I have gleaned: cstates are reduced-power modes of the CPU, with 0 representing the standard full-power operating state and higher numbers meaning greater power reduction through underclocking and voltage reduction. So in a theoretical sense, max_cstate=3 would almost certainly be better for battery life than max_cstate=0, but how much better and in what cases, I couldn't tell ya.

However, intel_idle.max_cstate=0 is a flag to the intel_idle kernel module to turn itself off completely, leaving power management to the acpi_idle module. It's possible that a fully-functional acpi_idle module might be better for your battery than a throttled-back intel_idle module, I don't know.

- dpk