I'm neither Frank nor Colin but I think I can answer this anyways ;-)
Jeremie Le Hen wrote:
Hi Frank, Hi Colin,
I recently installed sysutils/est and sysutils/estctrl (Enhanced
Speedstep Technology, kernel module and daemon) and it brought me
about 45 minutes more battery power.
Perhaps it's worth a try, if you don't already use it.
Could you tell us what it brings in regards to the FreeBSD cpufreq
framework please ?
est(4) has been reworked and integrated into cpufreq(4). The
functionality of estctrl(1) has been integrated into powerd(1). There is
no benefit of using est(4)/estctrl(1) over cpufreq(4)/powerd(1). Ok, if
your running anything older than 5.4-RELEASE, then there is no
There are, however, a few differences: est(4) is, in cpufreq(4) terms,
an "absolute driver". cpufreq(4) however might detect other "relative
drivers" like e.g. acpi_perf(4) and combine relative and absolute
drivers to create the list of available frequencies. This has the
effect, as Kevin Obermann has noted, that some apparently "lower"
frequencies might actually use more power than a "higher" frequency. For
instance, on my Pentium M 1.5 GHz, cpufreq(4) allows me to set the
frequency to e.g. 800 MHz or 750 MHz. 800 MHz would be a native
frequency of the CPU while 750 is .5 * 1500 MHz resulting from the
combination with (I think) p4tcc(4).
Personally, I find this very annoying b/c 750 MHz makes the fan spin
up more often than 800 MHz where I don't feel any difference in performance.
In order to work only with absulute drivers, i.e. emulate the est(4)
behaviour, use /boot/device.hints to disable all relative drivers your