Loading ...
Sorry, an error occurred while loading the content.

temp critical level

Expand Messages
  • roberto
    Ok but is it also possible to know if the temp is raising above a critical level for Pentium M 2.0 GHz? Thank you. linux-dell-laptops@yahoogroups.com ha
    Message 1 of 6 , Aug 12, 2005
    • 0 Attachment
      Ok
       
      but is it also possible to know if the temp is raising above a critical level for Pentium M 2.0 GHz?
       
      Thank you.

      linux-dell-laptops@yahoogroups.com ha scritto:

      Message: 5
      Date: Fri, 12 Aug 2005 14:03:34 +0200
      From: Sandro Dentella
      Subject: Re: hot pc very strange

      On Fri, Aug 12, 2005 at 01:45:52PM +0200, roberto wrote:
      >
      > Hi all, i use a laptop D600 with sarge 3.1 and kernel 2.6.8, but even if i
      > do not use any application, just the system running by itself, then after
      > 15 minutes, more or less, the fan starts to run very fast and the pc grows
      > very hot.
      >
      > 1. how to check the temp of the processor?

      cat /proc/acpi/thermal_zone/THM/temperature


      Roberto
      Debian Sarge
      kernel 2.6.8


      Yahoo! Mail: gratis 1GB per i messaggi, antispam, antivirus, POP3

    • Herman
      ... The critical temperature is the internal temperature of the silicon junctions in the processor chip. If the junctions get too hot, migration of impurities
      Message 2 of 6 , Aug 12, 2005
      • 0 Attachment
        roberto wrote:
        > Ok
        >
        > but is it also possible to know if the temp is raising above a critical
        > level for Pentium M 2.0 GHz?

        The critical temperature is the internal temperature of the silicon
        junctions in the processor chip. If the junctions get too hot,
        migration of impurities occur, causing the junctions to break down and
        lose their vital properties.

        A silicon junction temperature of up to 125C is OK. We only know the
        temperature of the heat sink, while the resistance between the heat sink
        and the junction is unknown. Therefore, you cannot know for sure
        whether the temperature of the junction is OK, but for a reasonably good
        thermal design, the junction temperature will be around 30C higher than
        the heat sink.

        However, common sense dictates that the temperature of the notebook PC
        should be kept to a level that is comfortable to the user. Since
        protein starts to cook at around 65C, it is a good idea not to exceed
        that temperature or the user will end up with burnt hands or legs, or
        the user may burn the varnish off his desk.

        Therefore, if the temperature sensor indicates a temperature of 75C at
        the heat sink, then the case temperature is probably around 50C and the
        junction temperature is probably around 105C - your PC would be hot to
        the touch, but OK.

        If you find that the temperature of the notebook is uncomfortable, then
        you can adjust the levels at which the fans would turn on. If the fans
        are reasonably quiet, then you could even run the at all times. I don't
        know how to change those parameters though I have done it in the long
        forgotten past - some Googling will find it.

        'Hope that explains things a little.

        H.

        --
        --
        Herman Oosthuysen, B.Eng(E), MIEEE
        Aerospace Software Ltd.
        #207, 908 -17th Ave. SW
        Calgary, AB, T2T 0A3, Canada
        Phone: 1.403.228-4181
        http://www.AerospaceSoftware.com
      • Paul Colestock
        Great explanation except for one thing, the increased junction temperature causes more generation of carriers in reversed biased junctions. Migration of
        Message 3 of 6 , Aug 12, 2005
        • 0 Attachment
            Great explanation except for one thing, the increased junction temperature causes more generation of carriers in reversed biased junctions.  Migration of impurities occurs at much higher temperatures.  Some of these excess carriers will recombine but some will create current across these junctions and once this process gets started, it lowers the junction barriers that then increases the traditional diode currents and the eventually these supposedly reversed biased junctions are forward biased.  At this point, the injection of carriers into the substrate turns on the parasitic bipolar transistor that hides beneath all cmos devices.  This parasitic bipolar essentially shorts out the cmos devices causing all cmos circuits to fail, not to mention that the current capacity of these parasitic bipolar is very high and thus steals current away from other vital cmos circuits.  In the end, the chip fails to provide it's intended function.  Sometimes it survives this event but sometimes this 'latchup" creates catastophic failures and your ic is gone forever (or the regulators that feed it).  What's the take away?  Keep it cool!

          Herman <herman@...> wrote:
          roberto wrote:
          > Ok

          > but is it also possible to know if the temp is raising above a critical
          > level for Pentium M 2.0 GHz?

          The critical temperature is the internal temperature of the silicon
          junctions in the processor chip.  If the junctions get too hot,
          migration of impurities occur, causing the junctions to break down and
          lose their vital properties.

          A silicon junction temperature of up to 125C is OK.  We only know the
          temperature of the heat sink, while the resistance between the heat sink
          and the junction is unknown.  Therefore, you cannot know for sure
          whether the temperature of the junction is OK, but for a reasonably good
          thermal design, the junction temperature will be around 30C higher than
          the heat sink.

          However, common sense dictates that the temperature of the notebook PC
          should be kept to a level that is comfortable to the user.  Since
          protein starts to cook at around 65C, it is a good idea not to exceed
          that temperature or the user will end up with burnt hands or legs, or
          the user may burn the varnish off his desk.

          Therefore, if the temperature sensor indicates a temperature of 75C at
          the heat sink, then the case temperature is probably around 50C and the
          junction temperature is probably around 105C  - your PC would be hot to
          the touch, but OK.

          If you find that the temperature of the notebook is uncomfortable, then
          you can adjust the levels at which the fans would turn on.  If the fans
          are reasonably quiet, then you could even run the at all times.  I don't
          know how to change those parameters though I have done it in the long
          forgotten past - some Googling will find it.

          'Hope that explains things a little.

          H.

          --
          --
          Herman Oosthuysen, B.Eng(E), MIEEE
          Aerospace Software Ltd.
          #207, 908 -17th Ave. SW
          Calgary, AB, T2T 0A3, Canada
          Phone: 1.403.228-4181
          http://www.AerospaceSoftware.com

          __________________________________________________
          Do You Yahoo!?
          Tired of spam? Yahoo! Mail has the best spam protection around
          http://mail.yahoo.com

        • Herman
          BTW, the magic info command is acpi -t: [herman@plato ~]$ acpi -t Battery 1: charged, 141% Thermal 1: ok, 71.0 degrees C [herman@plato ~]$ ... -- -- Herman
          Message 4 of 6 , Aug 12, 2005
          • 0 Attachment
            BTW, the magic info command is acpi -t:
            [herman@plato ~]$ acpi -t
            Battery 1: charged, 141%
            Thermal 1: ok, 71.0 degrees C
            [herman@plato ~]$


            Paul Colestock wrote:
            > Great explanation except for one thing, the increased junction
            > temperature causes more generation of carriers in reversed biased
            > junctions. Migration of impurities occurs at much higher temperatures.
            > Some of these excess carriers will recombine but some will create
            > current across these junctions and once this process gets started, it
            > lowers the junction barriers that then increases the traditional diode
            > currents and the eventually these supposedly reversed biased junctions
            > are forward biased. At this point, the injection of carriers into the
            > substrate turns on the parasitic bipolar transistor that hides beneath
            > all cmos devices. This parasitic bipolar essentially shorts out the
            > cmos devices causing all cmos circuits to fail, not to mention that the
            > current capacity of these parasitic bipolar is very high and thus steals
            > current away from other vital cmos circuits. In the end, the chip fails
            > to provide it's intended function. Som etimes it survives this event
            > but sometimes this 'latchup" creates catastophic failures and your ic is
            > gone forever (or the regulators that feed it). What's the take away?
            > Keep it cool!
            >
            > */Herman <herman@...>/* wrote:
            >
            > roberto wrote:
            > > Ok
            > >
            > > but is it also possible to know if the temp is raising above a
            > critical
            > > level for Pentium M 2.0 GHz?
            >
            > The critical temperature is the internal temperature of the silicon
            > junctions in the processor chip. If the junctions get too hot,
            > migration of impurities occur, causing the junctions to break down and
            > lose their vital properties.
            >
            > A silicon junction temperature of up to 125C is OK. We only know the
            > temperature of the heat sink, while the resistance between the heat
            > sink
            > and the junction is unknown. Therefore, you cannot know for sure
            > whether the temperature of the junction is OK, but for a reasonably
            > good
            > thermal design, the junction temperature will be around 30C higher than
            > the heat sink.
            >
            > However, common sense dictates that the temperature of th e notebook PC
            > should be kept to a level that is comfortable to the user. Since
            > protein starts to cook at around 65C, it is a good idea not to exceed
            > that temperature or the user will end up with burnt hands or legs, or
            > the user may burn the varnish off his desk.
            >
            > Therefore, if the temperature sensor indicates a temperature of 75C at
            > the heat sink, then the case temperature is probably around 50C and the
            > junction temperature is probably around 105C - your PC would be hot to
            > the touch, but OK.
            >
            > If you find that the temperature of the notebook is uncomfortable, then
            > you can adjust the levels at which the fans would turn on. If the fans
            > are reasonably quiet, then you could even run the at all times. I
            > don't
            > know how to change those parameters though I have done it in the long
            > forgotten past - some Googling will find it.
            >
            > 'Hope that explains things a little.
            >
            > H.
            >
            > --
            > --
            > Herman Oosthuysen, B.Eng(E), MIEEE
            > Aerospace Software Ltd.
            > #207, 908 -17th Ave. SW
            > Calgary, AB, T2T 0A3, Canada
            > Phone: 1.403.228-4181
            > http://www.AerospaceSoftware.com <http://www.aerospacesoftware.com/>
            >
            > __________________________________________________
            > Do You Yahoo!?
            > Tired of spam? Yahoo! Mail has the best spam protection around
            > http://mail.yahoo.com
            >
            > --------------------------------------------------------------
            > Please post your X config files in the group links or database
            > To unsubscribe, email: linux-dell-laptops-unsubscribe@yahoogroups.com
            > FAQ: http://www.whacked.net/ldl/faq
            >
            >
            > YAHOO! GROUPS LINKS
            >
            > * Visit your group "linux-dell-laptops
            > <http://groups.yahoo.com/group/linux-dell-laptops>" on the web.
            >
            > * To unsubscribe from this group, send an email to:
            > linux-dell-laptops-unsubscribe@yahoogroups.com
            > <mailto:linux-dell-laptops-unsubscribe@yahoogroups.com?subject=Unsubscribe>
            >
            > * Your use of Yahoo! Groups is subject to the Yahoo! Terms of
            > Service <http://docs.yahoo.com/info/terms/>.
            >
            >
            >


            --
            --
            Herman Oosthuysen, B.Eng(E), MIEEE
            Aerospace Software Ltd.
            #207, 908 -17th Ave. SW
            Calgary, AB, T2T 0A3, Canada
            Phone: 1.403.228-4181
            http://www.AerospaceSoftware.com
          • Alexander Toresson
            ... Umh... 71C is really hot. I ve got an inspiron 6000 with an 1.86ghz Pentium M, whose thermal is normally at 30-40C. Of course, it does also depends on
            Message 5 of 6 , Aug 13, 2005
            • 0 Attachment
              On 8/13/05, Herman <herman@...> wrote:
              > BTW, the magic info command is acpi -t:
              > [herman@plato ~]$ acpi -t
              > Battery 1: charged, 141%
              > Thermal 1: ok, 71.0 degrees C
              > [herman@plato ~]$
              >

              Umh... 71C is really hot. I've got an inspiron 6000 with an 1.86ghz
              Pentium M, whose thermal is normally at 30-40C. Of course, it does
              also depends on where it's placed.

              Regards, Alexander Toresson
            • Herman
              ... Yup - annoyingly hot. It cycles between 55C and 73C and so far I haven t found any way to change the fan trip points (Inspiron 1200). If anyone knows how,
              Message 6 of 6 , Aug 13, 2005
              • 0 Attachment
                Alexander Toresson wrote:
                > On 8/13/05, Herman <herman@...> wrote:
                >
                >>BTW, the magic info command is acpi -t:
                >>[herman@plato ~]$ acpi -t
                >> Battery 1: charged, 141%
                >> Thermal 1: ok, 71.0 degrees C
                >>[herman@plato ~]$
                >>
                >
                >
                > Umh... 71C is really hot.

                Yup - annoyingly hot. It cycles between 55C and 73C and so far I
                haven't found any way to change the fan trip points (Inspiron 1200).

                If anyone knows how, I'd be much obliged.

                Cheers,

                H.
              Your message has been successfully submitted and would be delivered to recipients shortly.