5-STABLE cpufreq hotter than est from ports

[Tijl Coosemans]

On Monday 08 August 2005 20:03, Kevin Oberman wrote:
> > From: Tijl Coosemans <tijl at ulyssis.org>
> > Date: Mon, 8 Aug 2005 16:18:00 +0200
> >
> > In my experience throttling doesn't really gain that much. There's
> > almost no difference between running at 600MHz/100% and
> > 600MHz/12.5%, except that it is 8 times slower, so I've set
> > debug.cpufreq.lowest to 400 to limit the performance drop.
>
> Odd. I don't see that at all. I am running at either 1.8 GHz or 1.2
> GHz and the performance ramps almost in lock-step with the setting
> and power consumption does, as well. Without your patch, using the
> values of dev.cpu.0.freq that run the CPU at the slower speed (1.2
> GHz), I get the following:
> dev.cpu.0.freq	Temp.	Savings
> 1200		73
> 1050		69	 5.5%
>  750		64	12.3%
>  600		62	15.1%
>  300		58	20.5%
>  150		54	25.0%
> The lowest 1.8 GHz value (1350) results in 85.I find these power
> savings to be significant.
>
> For power consumption I run the CPU at 100% until the CPU temperature
> stabilizes. I realize that this is only an approximation of power
> consumption, but I think it's close enough.

I've done this too now and I must admit throttling does seem to have an 
effect on power consumption, though it seems to be less and less 
effective with lower absolute settings.

1600/100%  (1600) 69°C
1600/12.5% (200)  55°C

600/100%   (600)  48°C
600/12.5%  (75)   45°C

For me, dropping to the lowest frequency (75MHz) is just way too 
expensive.