Linux users of Sony Z1 series

[Cyril Wattebled <>]

Hi there,

Rainer Jochem wrote:
> BTW: talking of CPU frequencies: What is the lowest cpu speed you can
> get out of your Z1 with Linux? I don't get it below 600MHz (which is 
> according to the docs in the speedstep-centrino kernel-driver where a
> Intel Datasheet is referenced the official lower limit for the
> processor if I've read it correctly) But when running WinXP on the
> laptop and having there the speedstepping activated and look at the
> System properties, Windows tells me that the processor is running at
> something about 280MHz... duh?!?... Perhaps the MHz counter is buggy
> which I doubt -- also because Windows tells me a remaining battery
> runtime of 5-6h (which is then really possible). 
>
> Perhaps there are some other things involved to throttle the CPU even
> slower than the 600MHz. If anyone has similar experience or know where
> to look for...

Well actually, I've been talking with some cpufreq developpers about 
this issue. Windows Frequency counter isn't buggy. It seems that Windows 
uses some kind of Cpu Frequency throttling along with the speedstep 
feature. This allows the processor the be not only a the lowest Cpu 
state for speedstep, but also to reach a lower frequency.
If you know a bit about cpufreq drivers, it would correspond to a mix of 
Enhanced speedstep and Clock modulation. For now, it's not possible to 
load 2 drivers at the same time but some guy told me it might be 
possible if someone wants to dig that way. Unfortunatly, no one wants to 
for now, well at least, amoung the guys who would have the knowledge to 
do so.

> Cheers,

Cheers,

--
Cyril Wattebled