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T500 thermal sensor locations?
Posted: Thu Apr 02, 2009 9:54 pm
by fmyhr
On my T500 type 2242 (P8400, GMA) running Linux:
# modprobe thinkpad-acpi
# cat /proc/acpi/ibm/thermal
temperatures: 39 36 32 -128 50 -128 29 -128 35 39 42 -128 -128 -128 -128 -128
It appears there are 7 or 8 thermal sensors, ignoring the -128 values and possibly the 50 which never seems to change. The first one seems to be cpu temperature. Anybody know about the others?
Thanks,
Frank
Re: T500 thermal sensor locations?
Posted: Sun Apr 05, 2009 1:34 pm
by fmyhr
After watching how the temperatures change as the machine warms up, starts/stops mprime etc. it appears that T500 sensor locations may be identical to those reported for the T61:
http://www.thinkwiki.org/wiki/Thermal_S ... inkPad_T61
Code: Select all
Index in "thermal" Location
1 CPU
2 MiniPCI
3 HDD
4 n/a (-128)
5 Battery 1
6 n/a (-128)
7 Battery 2
8 n/a (-128)
9 ?
10 ?
11 ?
12 n/a (-128)
13 n/a (-128)
14 n/a (-128)
15 n/a (-128)
16 n/a (-128)
In addition to the above, I'll hazard a guess that sensor 11 is perhaps the cpu heatsink. It is very closely correlated to cpu load but shows a lot more inertia than sensor 1 which changes almost instantaneously with cpu load.
On a related note, I'm seeing higher temperatures than I expected from sensor 1, about 70 C when running mprime with 2 threads. That's with the embedded controller setting fan speed around 3000 RPM. Setting the fan manually to "level 7" ~3450 RPM doesn't bring sensor1 temp down much but is significantly louder.
Here are the fan speeds I get for the manual levels:
Code: Select all
level rpm
0 0
1 1900
2 2700
3,4,5 3000
6,7 3450