Date: Fri, 18 Jul 2003 18:22:27 +0200 From: "Poul-Henning Kamp" <phk@phk.freebsd.dk> To: Tobias Roth <roth@iam.unibe.ch> Cc: mobile@freebsd.org Subject: Re: dmesg showing wrong frequency (IBM T30) Message-ID: <46000.1058545347@critter.freebsd.dk> In-Reply-To: Your message of "Fri, 18 Jul 2003 16:12:39 %2B0200." <20030718141239.GB19817@speedy.unibe.ch>
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In message <20030718141239.GB19817@speedy.unibe.ch>, Tobias Roth writes: >Hi > >On my IBM T30 1.8GHz, dmesg (with both 4.8 and 5.1) shows me this line: > >CPU: Intel(R) Pentium(R) 4 Mobile CPU 1.8GHz (1196.13-MHz 686-class CPU) > >Various windows utilities also claim that the cpu identification string >marks my cpu as 1.8 GHz unit, while the maximum frequency always gets >detected as something just below 1.2GHz. > >What is wrong here? To other IBM T30 users: Is your CPU identification >correct? What's "wrong" here is that the BIOS/ACPI firmware in your laptop runs your CPU at a reduced rate in order to make the battery last longer. Manufactureres have taken great care to not make it clear that the specs they give you are all reachable, _just_not_at_the_same_time_. You may be able to twiddle things in the BIOS or using ACPI and get faster CPU but less battery lifetime. It can also be that the case that the "cooling solution" (ie: fans, fins etc) does not work well enough and the ACPI code has slowed down the CPU in order to not melt anything [*]. In particular our ACPI code does not seem to always start fans when they should due to high temperatures. Poul-Henning [*] Known in certain circles as a "Warnering your laptop" :-) -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk@FreeBSD.ORG | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence.
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