Date: Sun, 02 May 2004 15:23:27 -0700 From: "Kevin Oberman" <oberman@es.net> To: James Snow <snow@teardrop.org> Cc: freebsd-mobile@freebsd.org Subject: Re: Laptop ACPI question Message-ID: <20040502222327.304EC5D07@ptavv.es.net> In-Reply-To: Your message of "Sun, 02 May 2004 01:22:51 EDT." <20040502052251.GA39933@teardrop.org>
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> Date: Sun, 2 May 2004 01:22:51 -0400 > From: James Snow <snow@teardrop.org> > > On Sat, May 01, 2004 at 02:05:36PM -0700, Kevin Oberman wrote: > > > > Actually, ACPI will greatly improve battery life soon, but not yet. The > > bits and pieces are being fed into CURRENT and I suspect that SpeedStep > > support will be coming soon. > > In the meantime, you can use sysctls to manually adjust CPU performance > > to enhance battery life. > > > > Look at: > > hw.acpi.cpu.throttle_max: 8 > > hw.acpi.cpu.throttle_state: 8 > > hw.acpi.cpu.cx_supported: C1/0 C2/1 C3/85 > > hw.acpi.cpu.cx_lowest: 0 > > hw.acpi.cpu.cx_history: 1453705/0 0/0 0/0 > > Hmm. In 5.2.1-p5, I don't have anything under hw.acpi.cpu > labeled .throttle*. I do, however, have these: > > hw.acpi.cpu.max_speed: 8 > hw.acpi.cpu.current_speed: 1 > hw.acpi.cpu.performance_speed: 8 > hw.acpi.cpu.economy_speed: 1 > > acpi(4) seems to suggest that these will alter CPU speed, > and presumably battery life as well. Is this not the case? I suspect that this simply indicates differences between systems. These settings look a lot like the older, less granular APM controlled services. I'd certainly try adjusting hw.acpi.cpu.current_speed and see what effect it has, but it looks to me like it's running at its economy mode, already.
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