PowerNow in mobile AthlonXP

[Kevin Oberman]

> Date: Thu, 11 Mar 2004 13:05:57 -0500
> From: Scott Lambert <lambert at lambertfam.org>
> Sender: owner-freebsd-mobile at freebsd.org
> 
> On Thu, Mar 11, 2004 at 09:17:11AM +0100, antic_eye wrote:
> > Hi there,
> > 
> > I googled all the web for a solution, so I hope you could help me. I
> > have a PackardBell Laptop with a mobile athlon xp inside. I installed
> > FreeBSD 5.2.1 3 weeks ago and everything works fine. Even the screen
> > flickering under x I fixed (it lasts me one week :o)).
> > 
> > My problem is, that I dont know how to trottle the cpu frequency. Linux
> > has the cpufreqd. Is there anything appropriate in BSD? ACPI is up and
> > running (expect the StandBy mode - it doesn't work)
> 
> I think Nate Lawson is working on getting a generic CPU frequency
> maniplation system added.  My athlon laptop also runs full speed all the
> time and has no throttle options in the acpi sysctls.
> 
> hw.acpi.cpu.cx_supported: C1/0
> hw.acpi.cpu.cx_lowest: 0
> hw.acpi.cpu.cx_history: 42619368/0
> 
> I am patiently awaiting Nate's code so that I can convince my CPU fan to
> at least slow down.  It is somewhat annoying at it's current level.
> 
> I think he's making some progress.  He made a commit a few days ago that
> looked like it might be the first step, newbusification of the CPUs.

While only P4m/Centrino platforms support the "deep sleep" modes you
cite above, all do support CPU throttling which is more widely
available.
hw.acpi.cpu.throttle_max: 8
hw.acpi.cpu.throttle_state: 8

Setting the throttle_state to a lower value will slow the system, but
will enhance battery life. The lowest value is '1' which is dog slow.
(12% of full speed with a max of 8.) This seems more widely available
than the deep sleep mode.
-- 
R. Kevin Oberman, Network Engineer
Energy Sciences Network (ESnet)
Ernest O. Lawrence Berkeley National Laboratory (Berkeley Lab)
E-mail: oberman at es.net			Phone: +1 510 486-8634