Date: Mon, 22 Dec 2008 21:45:55 +0200 From: Alexander Motin <mav@FreeBSD.org> To: Dmitry Kolosov <ivakras1@gmail.com> Cc: freebsd-acpi@freebsd.org Subject: Re: Problem on AMD64 Message-ID: <494FEE73.906@FreeBSD.org> In-Reply-To: <1229973789.00051301.1229963402@10.7.7.3> References: <20081221233822.7E92545020@ptavv.es.net> <1229973789.00051301.1229963402@10.7.7.3>
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Dmitry Kolosov wrote: > Could you give to us some links about powersaving with EST? For now, i'm using > powerd: > powerd_enable="YES" > powerd_flags="-a maximum -b adaptive -n adaptive -r 30 -i 35" > in my rc.conf. I'm not on AMD64, so i'm sorry, powerd works well to me (125 MHz > on battery and 2.16GHz on AC), BUT battery life time is equal in both cases and > something about 50 minutes, so i think powerd is not so powerfull for me. powerd uses any frequency control features provided by kernel. On P4 and above kernel may provide both EST and P4TCC frequencies. You can see them by `sysctl -a | grep freq`. P4TCC usually gives very small power benefit on idle CPU. I have seen benefit only on old P4 without or later with disabled C1E mode support. For CPUs with C1E support P4TCC is not effective as CPU anyway completely disables it's frequency on C1 state (HALT instruction). EST instead is much more effective as it also controls CPU voltage. Check your boot messages and sysctls for EST support. -- Alexander Motin
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