Re: CPU default frequency is at 75%
> Ondemand, the same as what appears in the applet, after boot.
> However, despite "Ondemand", even a huge CPU load does not make Debian
> asking for more CPU resources, such as 100%.
Notice that "ondemand" and such are completely implemented inside the
kernel. So all the relevant parameters are in
/sys/devices/system/cpu/cpu0/cpufreq/.
> As I explained before, there is no modification about CPU frequency,
> even with a maximum load.
That's odd. Unless your load is "nice"d, in which case it's not
considered as speed critical and will not cause the CPU frequency to
be increased.
>> I suggest you use just the ondemand governor and stop caring about the
>> issue at all. You will get full CPU power when you need it and save a
>> little power when you don't.
> My aim is not to save power. I am running many scientific-purpose
> applications, and they need full CPU power. As I often switch between
> many OSes, manually modifying manually governor is tedious. I
> installed kpowersave, and it works, but I am pretty deceived that it
> does not work with GNOME's utils.
There are lots of different scripts/programs/packages that can control
your CPU's frequency. If you set your system's frequency via the
cpufrequtils package, then just create or edit the file
/etc/default/cpufrequtils and put:
GOVERNOR="performance"
in it. I personally put MIN_SPEED="2.2GHz" in mine instead, because
I want to save energy but my system seems to have a problem which makes
it crash occasionally (more specifically I see memory corruption) for
any CPU frequency lower than 2.2GHz.
>> A question that comes to my mind: how do you measure the current clock
>> frequency? Only by looking at the Gnome applet?
> On one hand, by looking at the GNOME applet. On the other hand, by
> hearing fans, which are really noisy when I use "Performance" rather
> than "Ondemand".
Obviously, you disagree, but personally I'd prefer my long-running
calculations to take up 33% more time (by running at only 75%), if that
saved me from suffering through noisy fans.
Unless of course the machine is far away and you can't hear it. ;-)
Stefan
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