CPUs with variable speed clocks ?

[Dave Johnson]

Thomas Charron writes:
>   Aye, the Intel Core 2 Duo's have 'Advanced Intel Speedstep' capabilities.
> The clock can be dynamically modified by multipliers, I believe up to 8
> different speeds.  I'll give you more info as I investigate it, as the
> kernel I built last night I enabled for it.
> 
>   Thomas
> 

speedstep and powernow work fine under linux, but usually require a
kernel that knows about your sepecific cpu.

Auto-detection isn't fully baked, and I have to load the appropriate
modules, but it works fine after that.

in my case:
* cpufreq_userspace
* powernow-k8

On my X2 I get 4 speed choices and both cores need to run the same
speed:

pmg-alliance:10002:/sys/devices/system/cpu/cpu0/cpufreq/ cat scaling_available_frequencies 
2200000 2000000 1800000 1000000 
pmg-alliance:10003:/sys/devices/system/cpu/cpu0/cpufreq/ cat scaling_cur_freq 
1000000
pmg-alliance:10004:/sys/devices/system/cpu/cpu0/cpufreq/ cat affected_cpus 
0 1

I'd recomend powernowd (v0.97) using the userspace governor, but there
are other choices out there.

-- 
Dave