ondemand vs conservative

[Shane Fagan]

Well we could do a preference mode in the power manager or something...

--fagan

On Wed, 2010-09-29 at 17:05 -0400, Daniel Hollocher wrote:
> Yeah, I saw that.  I think that is also on wikipedia.  So maybe
> ondemand is for battery usage.  It would still be nice to have
> conservative for plugged in situations, like a desktop.
> 
> I did try to google first, I just didn't see a clear answer.
> 
> Dan
> 
> On Wed, Sep 29, 2010 at 4:54 PM, Siegfried-Angel Gevatter Pujals
> <siegfried at gevatter.com> wrote:
> > Hey,
> >
> > Google gives me this:
> > http://www.thinkwiki.org/wiki/How_to_make_use_of_Dynamic_Frequency_Scaling
> >
> > "The ondemand (available since 2.6.10) and conservative (since 2.6.12)
> > are governors based on in kernel implementations of CPU scaling
> > algorithms: they scale the CPU frequencies according to the needs
> > (like does the userspace frequency scaling daemons, but in kernel).
> > They differs in the way they scale up and down. The ondemand governor
> > switches to the highest frequency immediately when there is load,
> > while the conservative governor increases frequency step by step.
> > Likewise they behave the other way round for stepping down frequency
> > when the CPU is idle. The conservative governor is good for battery
> > powered environments on AMD64 (but may not work on older ThinkPads
> > like the T21). Ondemand may not work on older laptops without Enhanced
> > SpeedStep due to latency reasons. Anyway, for recent enough Intel CPU,
> > ondemand is the one recommended for power efficiency (over userspace,
> > and even over "powersave") by the Intel's kernel developer Arjan van
> > de Ven"
> >
> > --
> > Siegfried-Angel Gevatter Pujals (RainCT)
> > Free Software Developer       363DEAE3
> >
> 
> 
> 
> -- 
> "I'm not judgmental, I'm just excited about your quest for self improvement"
>