Re: enhanced intel speedstep feature was Re: speedstep-centrino on dothan

[Joseph Pingenot <trelane@digitasaru.net>]

>From Dominik Brodowski on Thursday, 07 July, 2005:
>On Thu, Jul 07, 2005 at 03:51:17PM -0500, Joseph Pingenot wrote:
>> >Just a latest question: can be p4-clockmod used together with
>> >speedstep-centrino? If not, would it make any sense to patch
>> >speedstep-centrino to use this feature too?
>> I'm a little confused.  How is this different from the ACPI CPU throttling
>>   states (/proc/acpi/processor/CPUn/limit to set, throttling to see all
>>   T-states available)?
>T-states _tend_ to be utilized using chipset logic, while p4-clockmod is
>done in-CPU.
>> On my 1.5-year-old Pentium-M, frequency scaling and T-states are different
>>   beasties, and act entirely differently.  I'm currently in the process of
>>   rewriting my governor's brain to deal with the two more intelligently.
>In your case, I would care about throttling. In very most cases it actually
>increases energy consumption, as the state being entered is technically the
>same to ACPI C2 (IIRC), so it is only "forced" idling and only useful if
>"forced" idling is needed to not need active cooling.

Why would this cause more energy consumption?

-Joseph

-- 
trelane@digitasaru.net--------------------------------------------------
          Graduate student in physics, Free Software developer.