Date: Wed, 1 Jan 2003 06:29:35 -0800 (PST) From: Hiten Pandya <hitmaster2k@yahoo.com> To: hubert@tournier.org, David Malone <dwmalone@FreeBSD.org> Cc: freebsd-bugs@FreeBSD.org Subject: Re: i386/46222: CPU speed incorrectly reported Message-ID: <20030101142935.910.qmail@web21108.mail.yahoo.com> In-Reply-To: <3E0C71B4.3000003@online.fr>
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--- Hubert Tournier <hubert.tournier@online.fr> wrote: > >Synopsis: CPU speed incorrectly reported > >State-Changed-From-To: open->feedback > >State-Changed-By: dwmalone > >State-Changed-When: Mon Dec 23 02:57:24 PST 2002 > >http://www.freebsd.org/cgi/query-pr.cgi?pr=46222 > > Hello David and thanks for your answer ! > > >The speed of the CPU is actually measured by seeing how many > >instructions are executed in an interval measured by the real time > >timer. This suggests that either your CPU is running slow or the > >timer is running fast. > >The CPU could be running slow because of APM or ACPI settings > >reducing power consumption by slowing the CPU. Can you look into > >this possibility? > > After modifying the hardware BIOS setup from > "Battery Save Mode = Low Power" to "Full Power" > instead of getting : > > Timecounter "TSC" frequency 184530035 Hz > CPU: Pentium II/Pentium II Xeon/Celeron (184.53-MHz 686-class CPU) > > I get the correct answer: > > Timecounter "TSC" frequency 366597251 Hz > CPU: Pentium II/Pentium II Xeon/Celeron (366.60-MHz 686-class CPU) > > The strange things are: > > 1) that I'm not running on battery but on AC power so (if I understand > correctly) this setting should not be relevant > 2) that with the same hardware settings (if my memory doesn't play tricks > on me), the FreeBSD 4.7-RELEASE previously installed on this machine > reported the correct speed > > Perhaps the ACPI code doesn't detect that the laptop is running on AC > power ? > > In either BIOS settings, after booting sysctl said and now says that the > machine is running at full speed : > > hw.acpi.cpu.max_speed: 8 > hw.acpi.cpu.current_speed: 8 > hw.acpi.cpu.performance_speed: 8 > hw.acpi.cpu.economy_speed: 4 > > But it the first case, perhaps it was at full half-speed :-) > > PS: I'm not running the APM daemon and my kernel does not include > "device apm". > > Have a nice day ! I think this should be FAQ Entry; because this happens with some Compaq Laptops. That is, the CPU Speed is reported lower when running in battery (power-saving) mode and vice versa. -- Hiten __________________________________________________ Do you Yahoo!? Yahoo! Mail Plus - Powerful. Affordable. Sign up now. http://mailplus.yahoo.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-bugs" in the body of the message
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