CPU C4 vs. C3 states, BIOS support and 1.5W power savings

[Adam Sloboda]

On Thu, 21 Jun 2007 15:32:49 +0300
"Török Edvin" <edwintorok at gmail.com> wrote:

> On 6/21/07, Adam Sloboda <ja at disorder.sk> wrote:
> >
> > It's the same and powertop never shows C4.  I have ThinkPad Z61m
> > with Core 2 Duo (T5500).
> 
> Is it Intel 945PM, or Intel 945GM? I have an Intel 945GM.
> 

It's 945GM.

> > BTW should be CPU idle power consumption same regardless of
> > frequency? I can see the difference only under load.
> 
> AFAIK P-States (freq changes) only have effect in C0, so it makes a
> difference whenever your CPU is running some program (when it is in
> C0). So unless you don't intend to run anything on the laptop, using
> the P-state transitions is useful ;)

That sounds reasonable :)  I'm using P-states but I wasn't sure why
it doesn't make any difference...

Adam