amdtemp does not find my CPU.

Jim Ohlstein jim at
Fri Mar 15 19:16:24 UTC 2013

On 3/15/13 12:15 PM, Zoran Kolic wrote:
> After I installed 9.1 amd64 on node with amd 8120,
> I was not able to read temperatures out of the box.
> I fetched source for head module and compiled. And
> loaded module. Still nothing. I assume my cpu is
> a bit different.
> Best regards

The module from head "works" for me with an 8120 on 9.1 stable (r247893)
though the results are inconsistent. I am not certain of how useful they

# sysctl hw.model
hw.model: AMD FX(tm)-8120 Eight-Core Processor

# kldstat | grep amd
 5    1 0xffffffff8183e000 1043     amdtemp.ko

# sysctl -a | grep dev.amdtemp
dev.amdtemp.0.%desc: AMD CPU On-Die Thermal Sensors
dev.amdtemp.0.%driver: amdtemp
dev.amdtemp.0.%parent: hostb4
dev.amdtemp.0.sensor_offset: 0
dev.amdtemp.0.core0.sensor0: 47.7C

Here are results taken at 0.1 second intervals using a shell script:

dev.amdtemp.0.core0.sensor0: 42.1C
dev.amdtemp.0.core0.sensor0: 42.2C
dev.amdtemp.0.core0.sensor0: 42.0C
dev.amdtemp.0.core0.sensor0: 42.1C
dev.amdtemp.0.core0.sensor0: 41.8C
dev.amdtemp.0.core0.sensor0: 41.7C
dev.amdtemp.0.core0.sensor0: 51.1C
dev.amdtemp.0.core0.sensor0: 51.0C
dev.amdtemp.0.core0.sensor0: 50.7C
dev.amdtemp.0.core0.sensor0: 50.5C
dev.amdtemp.0.core0.sensor0: 50.1C
dev.amdtemp.0.core0.sensor0: 49.8C
dev.amdtemp.0.core0.sensor0: 49.5C
dev.amdtemp.0.core0.sensor0: 49.2C
dev.amdtemp.0.core0.sensor0: 49.2C

and again:

dev.amdtemp.0.core0.sensor0: 41.5C
dev.amdtemp.0.core0.sensor0: 41.2C
dev.amdtemp.0.core0.sensor0: 40.8C
dev.amdtemp.0.core0.sensor0: 40.8C
dev.amdtemp.0.core0.sensor0: 41.0C
dev.amdtemp.0.core0.sensor0: 41.3C
dev.amdtemp.0.core0.sensor0: 41.6C
dev.amdtemp.0.core0.sensor0: 41.3C
dev.amdtemp.0.core0.sensor0: 54.0C
dev.amdtemp.0.core0.sensor0: 53.7C
dev.amdtemp.0.core0.sensor0: 53.3C
dev.amdtemp.0.core0.sensor0: 53.1C
dev.amdtemp.0.core0.sensor0: 52.7C
dev.amdtemp.0.core0.sensor0: 52.3C
dev.amdtemp.0.core0.sensor0: 52.1C
dev.amdtemp.0.core0.sensor0: 51.7C
dev.amdtemp.0.core0.sensor0: 51.5C

You can see during each series there are sudden increases of over 9C and
almost 13C respectively.

The same effect is seen if I track any of the individual cores with
"dev.cpu.[0-7].temperature". Here's an example with a 9C jump in 0.1 second.

dev.cpu.3.temperature: 41.5C
dev.cpu.3.temperature: 41.5C
dev.cpu.3.temperature: 41.7C
dev.cpu.3.temperature: 41.7C
dev.cpu.3.temperature: 41.3C
dev.cpu.3.temperature: 41.0C
dev.cpu.3.temperature: 40.7C
dev.cpu.3.temperature: 49.8C
dev.cpu.3.temperature: 49.5C
dev.cpu.3.temperature: 49.2C
dev.cpu.3.temperature: 48.8C
dev.cpu.3.temperature: 48.6C
dev.cpu.3.temperature: 48.2C
dev.cpu.3.temperature: 48.0C

I don't have hands on access to this box as it's in a datacenter 1000
miles from me, but the techs there had a look and all "seems to be OK".

Jim Ohlstein

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