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Based on kernel version 3.16. Page generated on 2014-08-06 21:39 EST.

1	Kernel driver k8temp
2	====================
3	
4	Supported chips:
5	  * AMD Athlon64/FX or Opteron CPUs
6	    Prefix: 'k8temp'
7	    Addresses scanned: PCI space
8	    Datasheet: http://support.amd.com/us/Processor_TechDocs/32559.pdf
9	
10	Author: Rudolf Marek
11	Contact: Rudolf Marek <r.marek@assembler.cz>
12	
13	Description
14	-----------
15	
16	This driver permits reading temperature sensor(s) embedded inside AMD K8
17	family CPUs (Athlon64/FX, Opteron). Official documentation says that it works
18	from revision F of K8 core, but in fact it seems to be implemented for all
19	revisions of K8 except the first two revisions (SH-B0 and SH-B3).
20	
21	Please note that you will need at least lm-sensors 2.10.1 for proper userspace
22	support.
23	
24	There can be up to four temperature sensors inside single CPU. The driver
25	will auto-detect the sensors and will display only temperatures from
26	implemented sensors.
27	
28	Mapping of /sys files is as follows:
29	
30	temp1_input - temperature of Core 0 and "place" 0
31	temp2_input - temperature of Core 0 and "place" 1
32	temp3_input - temperature of Core 1 and "place" 0
33	temp4_input - temperature of Core 1 and "place" 1
34	
35	Temperatures are measured in degrees Celsius and measurement resolution is
36	1 degree C. It is expected that future CPU will have better resolution. The
37	temperature is updated once a second. Valid temperatures are from -49 to
38	206 degrees C.
39	
40	Temperature known as TCaseMax was specified for processors up to revision E.
41	This temperature is defined as temperature between heat-spreader and CPU
42	case, so the internal CPU temperature supplied by this driver can be higher.
43	There is no easy way how to measure the temperature which will correlate
44	with TCaseMax temperature.
45	
46	For newer revisions of CPU (rev F, socket AM2) there is a mathematically
47	computed temperature called TControl, which must be lower than TControlMax.
48	
49	The relationship is following:
50	
51	temp1_input - TjOffset*2 < TControlMax,
52	
53	TjOffset is not yet exported by the driver, TControlMax is usually
54	70 degrees C. The rule of the thumb -> CPU temperature should not cross
55	60 degrees C too much.
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