C-states on Intel(R) Pentium(R) M processor

Fri May 18 07:40:41 PDT 2007

On Friday 18 May 2007 15:45:48 Arjan van de Ven wrote:
> Michiel de Bruijne wrote:
> > Does anyone know how many C-states an Intel(R) Pentium(R) M processor
> > should have?
>
> Mine has 4
>
> > I see only C0, C1 and C2. Are there any (kernel) options that have any
> > influence on how many C-states are available or is it only the BIOS/CPU?
>
> it's mostly a bios thing. Some bioses hide c3/c4 when on AC power, and
> some bioses only show a C3 which is really a C4 underneath when on
> battery:(

Ok, thanks!

I see only C0, C1 and C2 when on battery and AC. If the BIOS from my HP Compaq 
NX9030 Notebook is the cause, does that mean that due to the BIOS the power 
savings are not optimal or that I'm just unable to see it?