On Sun, Jan 11, 2009 at 04:36:42PM +1100, Pigeon wrote: > I have a laptop (ASUS W7J) with an Intel Core2 T7200 2GHz. > > When I'm using the acpi-cpufreq for cpufreq, I get (from > cpufreq-info): > > available frequency steps: 1.99 GHz, 1.66 GHz, 1.33 GHz, 996 MHz > > > When I use the p4-clockmod, I get: > > available frequency steps: 250 MHz, 500 MHz, 750 MHz, 1.00 GHz, 1.25 > GHz, 1.50 GHz, 1.75 GHz, 2.00 GHz > > > If I modprobe acpi-cpufreq first, then rmmod it, then modprobe > p4-clockmod, I get: > > available frequency steps: 125 MHz, 250 MHz, 375 MHz, 500 MHz, 625 > MHz, 750 MHz, 875 MHz, 1.00 GHz > > > I know acpi-cpufreq is recommended these days, so my question is is > it possible to get acpi-cpufreq to recognize more frequencies? Maybe all > the above? So those p4-clockmod frequencies? They aren't the actual frequencies the CPU is running at. Whichever one of those you set it to, your CPU will still be running at 2GHz. What those 'frequencies' are, are percentages of a duty cycle. So the 1GHz setting for eg is a 50% duty cycle. So for 50% of the time, the CPU is just sitting there doing nothing. During this time, it isn't at a lower frequency, and more importantly, it's not entering C states. In many cases, because of this latter point, you end up using _more_ power. Dave -- http://www.codemonkey.org.uk -- To unsubscribe from this list: send the line "unsubscribe cpufreq" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
