No C4 State with Powertop

[Arjan van de Ven]

bi0 wrote:
> Hi,
> 
> thank you for your answer. I'm testing powertop while I'm on battery
> power. The /sys/module/processor/parameters/max_cstate
> file tells me I should have 8 C-States. 

that's a bit of misinformation; 8 is how many LINUX would support, not 
your bios ;(

>So does my computer only use
> three, or are 5 of them shown as C-3? If so, is there
> a way to get more detailed information?

the best source is actually the spec sheet of your cpu unfortunately. 
The sad part is that the BIOS is inbetween linux and the hardware, and 
ACPI was designed to hide as much as possible here ;(

You can assume though that if you are on battery, the highest-number C 
state will map to the best your cpu can do; anything else would mean 
you have a REALLY sucky bios.