Hi Guys

[Sylvio César Teixeira Amorim]

Kevin,

  my laptop is Intel Core 2 duo 2.26, FSB 1066Mhz, DDR3.
my sysctl

hw.acipi.thermal.tz0._PSV: -1
hw.acipi.thermal.tz0._CRT: 107.0C



2009/5/13 Kevin Oberman <oberman at es.net>

> > Date: Wed, 13 May 2009 15:33:42 -0300
> > From: =?ISO-8859-1?Q?Sylvio_C=E9sar_Teixeira_Amorim?= <
> scjamorim at bsd.com.br>
> > Sender: owner-freebsd-acpi at freebsd.org
> >
> > I have one laptop Dell Latitude E4300 with FreeBSD-8-Current, The
> > temperature of the processor is very high when I'm compiling the kernel,
> I
> > get to stay with 88 Celsius, how do I force a download this temperature?
>
> Probably the first place to start is to clean the heat sink on your
> laptop. Simply opening the unit and blowing it out with compressed air
> can drop CPU temperature by over 10 degrees Celsius. This is probably
> something that should be done at least annually and more often if the
> laptop is run in dusty locations, such as sitting on a bed or table
> covered with a table cloth.
>
> It is also possible that the heatsink is not properly attached to the
> CPU. Several people have reported that cleaning and re-applying heatsink
> grease greatly improved the temperature.
>
> Next, take a look at the values of _PSV and _CRT. (sysctl hw.acpi). If
> PSV is higher than 88, your system is still within normal operating
> temperatures. For example, Pentium-M chips are speced to run at a steady
> temperature of 100C. _PSV on my laptop is 94.5C and _CRT is 99.0C. This
> means that the system does not start doing anything beyond normal fan
> cooling until the CPU reaches 94.5C and will reach 99C before starting
> to shutdown. (This is different from the emergency crowbar shutdown
> which is for thermal spikes of about 130-150C which might occur when a
> heatsink becomes dislodged.)
>
> When _PSV is reached, the system should simply slow down until the
> temperature drops. There is hysteresis to keep it from continually
> cycling. I don't recall numbers, though.
>
> If you want to lower the temperature "manually", you can kill powerd
> (/etc/rc.d/powerd stop) and set the CPU frequency lower. (sysctl
> dev.cpu.?.freq) where '?' is the CPU number. The available frequencies
> may be found in sysctl dev.cpu.0.freq_levels. If you are doing the
> manually, be sure to adjust all CPUs to the same frequency.
>
> Finally, placing the system on a surface that leaves an air gap under
> the system will help, too. Running it on a soft surface inhibits
> convection cooling and most soft surfaces are pretty goods thermal
> insulators.
> --
> R. Kevin Oberman, Network Engineer
> Energy Sciences Network (ESnet)
> Ernest O. Lawrence Berkeley National Laboratory (Berkeley Lab)
> E-mail: oberman at es.net                  Phone: +1 510 486-8634
> Key fingerprint:059B 2DDF 031C 9BA3 14A4  EADA 927D EBB3 987B 3751
>



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