ACPI temperature

[Taku YAMAMOTO]

On Fri, 4 Dec 2009 23:37:04 -0500
Steven Friedrich <freebsd at insightbb.com> wrote:

> I sent this to questions last Sunday, but only one person responded. He's 
> running FreeBSD 8 and I think his system is reporting bogus temps too.
> I think there might be a missing scaling factor. I'm a hardware guy, but I 
> don't currently have temperature measuring equipment and I would want to do it 
> on one of my towers (which are currently in storage), not my laptop anyway.
> 
> I booted my HP Pavilion zd8215us and I immediately invoked chkCPUTemperature.
> The first temp reported was 52C, which is 125.6F. This leads me to believe
> that acpi has an anomaly regarding temperature measurement. The ambient temp 
> was 71F (21.6C). The machine had been off for over eight hours.

I'd suggest to kldload coretemp.ko for another point of view; because it
directly retrieves the core temperature from MSR - no ACPI involved.

We can read the core temperature via sysctl dev.cpu.0.temperature like this:

 % sysctl dev.cpu.0.temperature hw.acpi.thermal.tz0.temperature
 dev.cpu.0.temperature: 58.0C
 hw.acpi.thermal.tz0.temperature: 46.0C

This is obtained from my ThinkPad X60 running in 19C (66.2F) ambient for 15
minutes with the lid closed, powerd running, C2 state enabled.

As others stated already, I too think 52C is not so high to worry, though.

# I think it is very convenient to have a knob (or better, honors LANG) to
# let sysctl show "IK" oids in Fahrenheit.

-- 
-|-__   YAMAMOTO, Taku
 | __ <     <taku at tackymt.homeip.net>

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