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@lists.fedoraproject.org >> 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 -- devel mailing list devel@lists.fedoraproject.org https://admin.fedoraproject.org/mailman/listinfo/devel
