On Mon, 27 Aug 2012 16:37:41 +0000 (UTC), jb wrote:
> Christian Mangin <christian.mangin <at> gmail.com> writes:
> > Le 27.08.2012 08:44, Mike Manilone a écrit :
> > > Hi all,
> > >
> > > I just switched from Fedora Linux to FreeBSD. But I noticed a problem,
> > > the CPU temperature will be very high when the load is high.
> > > Especially while I am building C++ programs. It shut down for even 3
> > > times while I was building Firefox/Thunderbird, just because of high
> > > temperature (86.5C).
Mike, 86.5C isn't really all that hot for a modern 4-core laptop under
load; like jb below, show us `sysctl -a | grep thermal` so we can see
its passive cooling and critical temperatures.
> > I used to have the same problem with my laptop (i5) and this can be
> > fixed by lowering the temperature threshold for passive cooling. (_PSV)
> >
> > hw.acpi.thermal.user_override=1
> > hw.acpi.thermal.tz0._PSV=80C
> >
> > You should try to adjust _PSV to be significantly lower (> 15-20C) than
> > the _CRT (critical shutdown temp) so that _CRT is never reached.
> >
> > Christian
Modulo adjusting the right thermal zone, this is safe advice; you can
always edge it up later, assuming it helps stay at say 10C below _CRT.
> I too have the same problem (Lenovo dual core r61i).
> You should see the relevant data before making any changes - below it is
> explained why.
>
> This is my data:
> $ sysctl -a | grep -i thermal
> hw.acpi.thermal.min_runtime: 0
> hw.acpi.thermal.polling_rate: 10
> hw.acpi.thermal.user_override: 0
> hw.acpi.thermal.tz0.temperature: 42.0C
> hw.acpi.thermal.tz0.active: -1
> hw.acpi.thermal.tz0.passive_cooling: 0
> hw.acpi.thermal.tz0.thermal_flags: 0
> hw.acpi.thermal.tz0._PSV: -1
> hw.acpi.thermal.tz0._HOT: -1
> hw.acpi.thermal.tz0._CRT: 127.0C
> hw.acpi.thermal.tz0._ACx: -1 -1 -1 -1 -1 -1 -1 -1 -1 -1
> hw.acpi.thermal.tz0._TC1: -1
> hw.acpi.thermal.tz0._TC2: -1
> hw.acpi.thermal.tz0._TSP: -1
> hw.acpi.thermal.tz1.temperature: 42.0C
> hw.acpi.thermal.tz1.active: -1
> hw.acpi.thermal.tz1.passive_cooling: 1
> hw.acpi.thermal.tz1.thermal_flags: 0
> hw.acpi.thermal.tz1._PSV: 95.5C
> hw.acpi.thermal.tz1._HOT: -1
> hw.acpi.thermal.tz1._CRT: 100.0C
> hw.acpi.thermal.tz1._ACx: -1 -1 -1 -1 -1 -1 -1 -1 -1 -1
> hw.acpi.thermal.tz1._TC1: 5
> hw.acpi.thermal.tz1._TC2: 4
> hw.acpi.thermal.tz1._TSP: 600
> dev.acpi_tz.0.%desc: Thermal Zone
> dev.acpi_tz.1.%desc: Thermal Zone
> dev.p4tcc.0.%desc: CPU Frequency Thermal Control
> dev.p4tcc.1.%desc: CPU Frequency Thermal Control
> $
>
> As you can see in my case:
> hw.acpi.thermal.tz0.passive_cooling: 0
> which is NOT available (so obviously any settings in tz0 zone are
> irrelevant).
That tz0 seems not to be a CPU, nor a fan. Maybe just informational?
> This is explained here:
> ACPI_THERMAL(4):
> ...
> hw.acpi.thermal.tz%d.passive_cooling
> If set to 1, passive cooling is enabled. It does cooling
> without
> fans using cpufreq(4) as the mechanism for controlling CPU
> speed.
> Default is enabled for tz0 where it is available.
> ...
>
> In my case tz1 zone is available and active.
And your _PSV 95.5C and _CRT 100.0C aren't uncommon sort of values these
days, hence my surprise at Mike's (apparent) CRT shutdown showing 86.5C.
On the other hand, even my 1133MHz P3-M can go from <50C to >60C inside
one 10-second polling interval under applied high load, so a shorter
hw.acpi.thermal.polling_rate may help trigger _PSV well before _CRT.
cheers, Ian
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