CPU temp

B

bgroper

How would I get correct cpu temp from this hardware ?

root@A8-7600 /root # sysctl -n hw.model
AMD A8-7600 Radeon R7, 10 Compute Cores 4C+6G
root@A8-7600 /root # kldload amdtemp
kldload: can't load amdtemp: module already loaded or in kernel
root@A8-7600 /root # sysctl -n dev.cpu.0.temperature
8.6C
root@A8-7600 /root #

System has been running and true temp should be in 30 ~ 40 degree range.
 
Strange that sysctl -n dev.cpu.0.temperature was reporting correct temperature for this CPU until around ~ early August 2025.
Then it became borked.
Can't remember what was updated in early August.
 
This is documented in the AMDTEMP(4)
CAVEATS
For Family 10h and later processors, "(the reported temperature) is a
non-physical temperature measured on an arbitrary scale and it does not
represent an actual physical temperature like die or case temperature.
Instead, it specifies the processor temperature relative to the point
at which the system must supply the maximum cooling for the processor's
specified maximum case temperature and maximum thermal power
dissipation" according to BIOS and Kernel Developer's Guide (BKDG) for
AMD Processors,
Click to expand...
 
bgroper said:
How would I get correct cpu temp from this hardware ?

root@A8-7600 /root # sysctl -n hw.model
AMD A8-7600 Radeon R7, 10 Compute Cores 4C+6G
root@A8-7600 /root # kldload amdtemp
kldload: can't load amdtemp: module already loaded or in kernel
root@A8-7600 /root # sysctl -n dev.cpu.0.temperature
8.6C
root@A8-7600 /root #

System has been running and true temp should be in 30 ~ 40 degree range.
Click to expand...
On mine AMD Ryzen 5 PRO 3500U w/ Radeon Vega Mobile Gfx it shows correct IMO. At this momment is 41.6C
 
This gets curiouser and curiouser.

root@A8-7600 /root # inxi -Cs
CPU:
Info: quad core model: AMD A8-7600 Radeon R7 10 Compute Cores 4C+6G bits: 64 type: MCP cache:
L2: 4 MiB note: check
Speed (MHz): 3094 min/max: N/A cores: No OS support for core speeds.
Sensors:
System Temperatures: cpu: 19.0 C mobo: N/A
Fan Speeds (RPM): N/A
root@A8-7600 /root # sysctl -n dev.cpu.0.temperature
9.1C
root@A8-7600 /root #
 
# uname -a
FreeBSD trx50 14.3-RELEASE FreeBSD 14.3-RELEASE releng/14.3-n271432-8c9ce319fef7 GENERIC amd64
# dmesg -a
---<<BOOT>>---
Copyright (c) 1992-2023 The FreeBSD Project.
Copyright (c) 1979, 1980, 1983, 1986, 1988, 1989, 1991, 1992, 1993, 1994
The Regents of the University of California. All rights reserved.
FreeBSD is a registered trademark of The FreeBSD Foundation.
FreeBSD 14.3-RELEASE releng/14.3-n271432-8c9ce319fef7 GENERIC amd64
FreeBSD clang version 19.1.7 (https://github.com/llvm/llvm-project.git llvmorg-19.1.7-0-gcd708029e0b2)
VT(efifb): resolution 800x600
CPU: AMD Ryzen Threadripper 9960X 24-Cores (4200.20-MHz K8-class CPU)

# kldstat
Id Refs Address Size Name
1 74 0xffffffff80200000 1f41458 kernel
2 1 0xffffffff82142000 5e9340 zfs.ko
3 1 0xffffffff8272c000 7618 amdtemp.ko
4 2 0xffffffff82734000 36e0 amdsmn.ko
5 1 0xffffffff82739000 7808 cryptodev.ko
6 1 0xffffffff83268000 3390 acpi_wmi.ko
7 1 0xffffffff8326c000 6020 ig4.ko
8 1 0xffffffff83273000 3220 intpm.ko
9 1 0xffffffff83277000 2178 smbus.ko
10 1 0xffffffff8327a000 b6e0 if_lagg.ko
11 1 0xffffffff83286000 20c0 if_infiniband.ko
12 1 0xffffffff83289000 3360 uhid.ko
13 1 0xffffffff8328d000 4364 ums.ko
14 1 0xffffffff83292000 3360 wmt.ko
15 1 0xffffffff83296000 5640 ng_ubt.ko
16 7 0xffffffff8329c000 abb8 netgraph.ko
17 3 0xffffffff832a7000 a250 ng_hci.ko
18 4 0xffffffff832b2000 2670 ng_bluetooth.ko
19 1 0xffffffff832b5000 e268 ng_l2cap.ko
20 1 0xffffffff832c4000 1bf98 ng_btsocket.ko
21 1 0xffffffff832e0000 3908 ng_socket.ko
22 1 0xffffffff832e4000 2a80 mac_ntpd.ko

# sysctl dev.cpu | grep temperature
#
nothing is found

Powerd is keeping the rig at 1500 MHz when doing nothing , any ideas on how how to monitor system temperature ?
 
Does it show dev.amdtemp nodes at all? Like this
Code: 
root@kg-core2:~ # sysctl dev.amdtemp
dev.amdtemp.0.ccd0: 58.0C
dev.amdtemp.0.core0.sensor0: 69.6C
dev.amdtemp.0.sensor_offset: 0
dev.amdtemp.0.%parent: hostb0
dev.amdtemp.0.%pnpinfo:
dev.amdtemp.0.%location:
dev.amdtemp.0.%driver: amdtemp
dev.amdtemp.0.%desc: AMD CPU On-Die Thermal Sensors
dev.amdtemp.%parent:
If not the amdtemp(4) driver doesn't correctly pick up the sensors in your cpu. I have had success previously (back in the k8 days) in communicating with a developer who fixed those problems. Perhaps OP can do the same?
 
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