Re: Inspiron 6000 and CPU power saving

[Michael (Micksa) Slade]

Pallipadi, Venkatesh wrote:

>  
>
> > -----Original Message-----
> > From: linux-kernel-owner@xxxxxxxxxxxxxxx 
> > [mailto:linux-kernel-owner@xxxxxxxxxxxxxxx] On Behalf Of 
> > Michael (Micksa) Slade
> > Sent: Sunday, October 15, 2006 7:18 PM
> > To: linux-kernel@xxxxxxxxxxxxxxx
> > Subject: Inspiron 6000 and CPU power saving
> >
> > I recently discovered that my Inspiron 6000 uses about 50% more power 
> > idling in linux than in windows XP.  This means its battery life is 
> > about 2/3 of what it could/should be.
> >
> > I guessed it might be the CPU, and did some tests.  The 
> > results strongly 
> > suggest as much.  These are the results I got for power consumption in 
> > various situations.
> >
> > linux idle at 800MHz: 27W        
> > linux idle at 1600MHz: 36W        
> > linux raytracing at 800: 30W
> > linux raytracing at 1600: 42W 
> >
> > windows idle (presumably 800MHz): 16W
> > windows raytracing (presumably 1600MHz): 36W
> >
> > I've tried ubuntu dapper and ubuntu edgy, and RIP 10 (rescue disk) and 
> > BBC 2.1 (rescue disk), and they all appear to have the same 
> > issue.  The 
> > machine's BIOS has no APM so I can't try it for comparison.
> >
> > I've tried noapic and "echo n > 
> > /sys/module/processor/parameters/max_cstate", where n is 1 thru 4.  
> > Neither appear to have any affect.
> >
> > I need help digging deeper.  I guess /proc/acpi/processor/CPU0/power 
> > could give some insight but I'm not sure how to read the 
> > numbers.  That 
> > and "learn about ACPI" is all I can figure out so far.
> >
> > So where to from here?  I am prepared to spend a significant amount of 
> > time researching and resolving the issue, so feel free to suggest 
> > reading the ACPI spec or whatever if that's what it's going to take.
> >
> > Mick.
> >
> >    
>
> Output of 
> #cat /proc/acpi/processor/CPU0/power/*
> And
> #cat /sys/devices/system/cpu/cpu0/cpufreq/*
> Will be a good starting point.
>
> Also, open a issue at bugme.osdl.org. It makes tracking the issues
> easier that way.
>
> Thanks,
> Venki
>  
Done.

http://bugzilla.kernel.org/show_bug.cgi?id=7393

As part of this I've also tried vanilla 2.6.19-rc2 and done another 
small test. See the report.

Mick.

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