k8temp.rst (2155B)
1Kernel driver k8temp 2==================== 3 4Supported chips: 5 6 * AMD Athlon64/FX or Opteron CPUs 7 8 Prefix: 'k8temp' 9 10 Addresses scanned: PCI space 11 12 Datasheet: https://www.amd.com/system/files/TechDocs/32559.pdf 13 14Author: Rudolf Marek 15 16Contact: Rudolf Marek <r.marek@assembler.cz> 17 18Description 19----------- 20 21This driver permits reading temperature sensor(s) embedded inside AMD K8 22family CPUs (Athlon64/FX, Opteron). Official documentation says that it works 23from revision F of K8 core, but in fact it seems to be implemented for all 24revisions of K8 except the first two revisions (SH-B0 and SH-B3). 25 26Please note that you will need at least lm-sensors 2.10.1 for proper userspace 27support. 28 29There can be up to four temperature sensors inside single CPU. The driver 30will auto-detect the sensors and will display only temperatures from 31implemented sensors. 32 33Mapping of /sys files is as follows: 34 35============= =================================== 36temp1_input temperature of Core 0 and "place" 0 37temp2_input temperature of Core 0 and "place" 1 38temp3_input temperature of Core 1 and "place" 0 39temp4_input temperature of Core 1 and "place" 1 40============= =================================== 41 42Temperatures are measured in degrees Celsius and measurement resolution is 431 degree C. It is expected that future CPU will have better resolution. The 44temperature is updated once a second. Valid temperatures are from -49 to 45206 degrees C. 46 47Temperature known as TCaseMax was specified for processors up to revision E. 48This temperature is defined as temperature between heat-spreader and CPU 49case, so the internal CPU temperature supplied by this driver can be higher. 50There is no easy way how to measure the temperature which will correlate 51with TCaseMax temperature. 52 53For newer revisions of CPU (rev F, socket AM2) there is a mathematically 54computed temperature called TControl, which must be lower than TControlMax. 55 56The relationship is following: 57 58 temp1_input - TjOffset*2 < TControlMax, 59 60TjOffset is not yet exported by the driver, TControlMax is usually 6170 degrees C. The rule of the thumb -> CPU temperature should not cross 6260 degrees C too much.