----- Original Message ----- > On 07/19/2011 09:59 AM, Jaroslav Skarvada wrote: > > ----- Original Message ----- > >> To avoid some confusion: > >> > >> I removed cpuspeed from Rawhide about 10 days ago. It no longer > >> serves > >> any > >> purpose in Fedora and has been effectively replaced by kernel > >> cpufreq > >> stack. > >> > >> All cpufreq modules should now be built-in, with ondemand being the > >> default > >> governor in Fedora. > >> > >> In case you would to use a different governor and/or specific > >> frequency, try the > >> new cpupower.service (provieded by cpupowerutils). Most people > >> shouldn't need > >> this, though. > >> > >> See https://bugzilla.redhat.com/show_bug.cgi?id=713572 for more > >> info. > >> > >> Regards, > >> -- > >> # Petr Sabata > >> > >> -- > >> devel mailing list > >> devel@xxxxxxxxxxxxxxxxxxxxxxx > >> https://admin.fedoraproject.org/mailman/listinfo/devel > > > > Sad that the daemon gone. It was able to dynamically switch speed > > (and save power) on systems that have CPUs with high transition > > latency (e.g. old P4, some Atoms, etc.). On such systems the > > Actually, no... > > http://codemonkey.org.uk/2009/01/18/forthcoming-p4clockmod/ > > > So the 1.00GHz ‘frequency’ is actually “run at 2GHz, but only do > > work 50% of the time”. > > > > On the surface, this sounds like a good idea. The other 50%, the CPU > > is idle, so you’re saving power, right? > > Not so much. In fact, you could be burning more power. The reason > > for this is that when the processor is sitting there doing nothing, > > it isn’t lower frequency, and more importantly, it very likely isn’t > > entering C states. So you’re burning the same amount of power, but > > now you’re only doing work for 50% of the time. As a result of this, > > your workload takes twice as long to complete. > > I've measured it, and Dave is right. You might get something saying > "1.0Ghz" but you're not saving anything at all. > > -Eric It is heating less, but you are not saving power? Sorry, but I cannot understand. The more energy consumed for the same computational load is another story Jaroslav -- devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxxx https://admin.fedoraproject.org/mailman/listinfo/devel
