Difference between revisions of "Thermal Sensors"

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(ThinkPad {{T43}}, {{T43p}})
(Sensor locations)
Line 24: Line 24:
 
This information is model specific.
 
This information is model specific.
  
===ThinkPad {{T43}}, {{T43p}}===
+
===ThinkPad {{R51}}===
Summary:
+
The [[ibm-acpi]] documentation includes the report by Thomas Gruber:
 
  EC offset  Index in "thermal"  Location (estimated)
 
  EC offset  Index in "thermal"  Location (estimated)
 
  0x78        1                    CPU
 
  0x78        1                    CPU
  0x79        2                    Between PCMCIA slot and CPU (same as HDAPS module)
+
  0x79        2                    Mini-PCI
  0x7A        3                    PCMCIA slot
+
  0x7A        3                    HDD
 
  0x7B        4                    GPU
 
  0x7B        4                    GPU
  0x7C        5                    Battery (front left)
+
  0x7C        5                    Battery
 
  0x7D        6                    n/a
 
  0x7D        6                    n/a
  0x7E        7                    Battery (rear right)
+
  0x7E        7                    Battery
 
  0x7F        8                    n/a
 
  0x7F        8                    n/a
  0xC0        none                Bus between Northbridge and DRAM
+
  0xC0        none                ?
  0xC1        none                Southbridge (under Mini-PCI card, under touchpad)
+
  0xC1        none                ?
  0xC2        none                Power circuitry, on underside of system board under F2 key
+
  0xC2        none                ?
{{gallery_start}}
 
{{thumb|T43-thermal-sensors.jpg|ThinkPad T43 sensor locations}}
 
{{thumb|T43-2668-thermal-sensors-zoom.jpg|ThinkPad T43 sensor locations detail}}
 
{{gallery_end}}
 
  
 
===ThinkPad {{T40}}===
 
===ThinkPad {{T40}}===
Line 58: Line 54:
 
  0xC2        none                n/a
 
  0xC2        none                n/a
  
===ThinkPad {{R51}}===
+
===ThinkPad {{T43}}, {{T43p}}===
The [[ibm-acpi]] documentation includes the report by Thomas Gruber:
+
Summary:
 
  EC offset  Index in "thermal"  Location (estimated)
 
  EC offset  Index in "thermal"  Location (estimated)
 
  0x78        1                    CPU
 
  0x78        1                    CPU
  0x79        2                    Mini-PCI
+
  0x79        2                    Between PCMCIA slot and CPU (same as HDAPS module)
  0x7A        3                    HDD
+
  0x7A        3                    PCMCIA slot
 
  0x7B        4                    GPU
 
  0x7B        4                    GPU
  0x7C        5                    Battery
+
  0x7C        5                    Battery (front left)
 
  0x7D        6                    n/a
 
  0x7D        6                    n/a
  0x7E        7                    Battery
+
  0x7E        7                    Battery (rear right)
 
  0x7F        8                    n/a
 
  0x7F        8                    n/a
  0xC0        none                ?
+
  0xC0        none                Bus between Northbridge and DRAM
  0xC1        none                ?
+
  0xC1        none                Southbridge (under Mini-PCI card, under touchpad)
  0xC2        none                ?
+
  0xC2        none                Power circuitry, on underside of system board under F2 key
 +
{{gallery_start}}
 +
{{thumb|T43-thermal-sensors.jpg|ThinkPad T43 sensor locations}}
 +
{{thumb|T43-2668-thermal-sensors-zoom.jpg|ThinkPad T43 sensor locations detail}}
 +
{{gallery_end}}

Revision as of 20:53, 17 January 2006

This page aims to summarize known information about the locations and properties of thermal sensors on ThinkPad laptops.

Accessing the sensors

ACPI system temperature sensors

The primary means of accessing the thermal sensors is through the ibm-acpi module, which provides up to 11 thermal sensors (some of which may be inactive) when loaded with the experimental=1 option. Up to eight thermal sensors are exposed at /proc/acpi/ibm/thermal:

# cat /proc/acpi/ibm/thermal
temperatures: 44 41 33 42 33 -128 30 -128

On some models there are three additional sensors at Embedded Controller offsets 0xC0 to 0xC2, which can be read by parsing /proc/acpi/ibm/ecdump:

# perl -ne 'm/^EC 0xc0: .(..) .(..) .(..) / or next; print hex($1)." ".hex($2)." ".hex($3)."\n"' < /proc/acpi/ibm/ecdump
40 48 43

HDAPS temperature sensor

The Active Protection System accelerometer also reports a temperature (but it is not certain that the sensor location is inside the HDAPS chip):

# cat /sys/bus/platform/drivers/hdaps/hdaps/temp1
41

Harddisks temperature sensor

Finally, the hard disk temperature can be read through the SMART interface:

# smartctl -A /dev/hda
194 Temperature_Celsius 0x0022 145 097 000 Old_age Always - 31

Sensor locations

This information is model specific.

ThinkPad R51

The ibm-acpi documentation includes the report by Thomas Gruber:

EC offset   Index in "thermal"   Location (estimated)
0x78        1                    CPU
0x79        2                    Mini-PCI
0x7A        3                    HDD
0x7B        4                    GPU
0x7C        5                    Battery
0x7D        6                    n/a
0x7E        7                    Battery
0x7F        8                    n/a
0xC0        none                 ?
0xC1        none                 ?
0xC2        none                 ?

ThinkPad T40

The location of one of the sensors is identified here.

EC offset   Index in "thermal"   Location (estimated)
0x78        1                    CPU
0x79        2                    System board under rear left corner of Mini-PCI module
0x7A        3                    ?
0x7B        4                    GPU
0x7C        5                    Battery
0x7D        6                    n/a
0x7E        7                    Battery
0x7F        8                    n/a
0xC0        none                 n/a
0xC1        none                 n/a
0xC2        none                 n/a

ThinkPad T43, T43p

Summary:

EC offset   Index in "thermal"   Location (estimated)
0x78        1                    CPU
0x79        2                    Between PCMCIA slot and CPU (same as HDAPS module)
0x7A        3                    PCMCIA slot
0x7B        4                    GPU
0x7C        5                    Battery (front left)
0x7D        6                    n/a
0x7E        7                    Battery (rear right)
0x7F        8                    n/a
0xC0        none                 Bus between Northbridge and DRAM
0xC1        none                 Southbridge (under Mini-PCI card, under touchpad)
0xC2        none                 Power circuitry, on underside of system board under F2 key

Photos (click to see full size)
ThinkPad T43 sensor locations
ThinkPad T43 sensor locations detail