Date: Fri, 21 Sep 2007 12:33:40 -0700 From: Jeremy Chadwick <koitsu@FreeBSD.org> To: Chuck Swiger <cswiger@mac.com> Cc: Rui Paulo <rpaulo@fnop.net>, Doug Barton <dougb@FreeBSD.org>, "Constantine A. Murenin" <cnst@FreeBSD.org>, Shteryana Shopova <syrinx@FreeBSD.org>, FreeBSD Current <freebsd-current@FreeBSD.org>, Alexander Leidinger <Alexander@leidinger.net> Subject: Re: GSoC2007: cnst-sensors.2007-09-13.patch Message-ID: <20070921193340.GA70365@eos.sc1.parodius.com> In-Reply-To: <C64CBF93-D333-414A-9B83-F0866EC6C150@mac.com> References: <200709132302.l8DN2Tv5076033@repoman.freebsd.org> <46E9FC0C.70607@FreeBSD.org> <alpine.BSF.0.9999.0709182210210.1003@ync.qbhto.arg> <46F1A96F.2040602@FreeBSD.org> <alpine.BSF.0.9999.0709201544440.1740@qbhto.arg> <B77D1A6C-23B1-46CA-BB49-AAC954B5264C@fnop.net> <C64CBF93-D333-414A-9B83-F0866EC6C150@mac.com>
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On Fri, Sep 21, 2007 at 12:20:07PM -0700, Chuck Swiger wrote: > The CPU itself has a thermal control circuit which puts the CPU into a > reduced duty cycle (ie, it reduces the core voltage and stops the CPU for > something like 10 clocks, and then allows one clock through) and continues > to run the CPU at about 10% of normal workload until the temperature falls > below the critical threshold. There's a good document here: Are you referring to the Core 2 Duo C1E (Enhanced Halt State) processor feature or the EIST feature? I'm guessing C1E. Note that for C1E to work, it has to be enabled/available in the BIOS. I'll add that C1E is really great, dropping temperatures during idle periods by about 5-6C from what I've seen. The additional C[234]E states (at least for desktops) don't provide much benefit, but C1E definitely does. -- | Jeremy Chadwick jdc at parodius.com | | Parodius Networking http://www.parodius.com/ | | UNIX Systems Administrator Mountain View, CA, USA | | Making life hard for others since 1977. PGP: 4BD6C0CB |
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