This is a 2012-era Chromebox with a replacement CPU (i7 3720qm 45Watt, instead of the stock i5 35Watt) that is now running a proxmox system with some self-hosted services (home assistant, frigate NVR, etc). It does not seem to be capable of scaling down the frequency of the CPU cores when it gets hot. This has led to occasional emergency thermal shutdowns, which I would like to avoid.
Here is what I have found out so far:
There is no EC in this system, but it is possible to use the it87 kernel module to get some control over the fan and visibility into temperature with the lm-sensors package and the sensors command. Getting this to work required the addition of an acpi parameter to the grub boot command:
GRUB_CMDLINE_LINUX_DEFAULT=“quiet acpi_enforce_resources=lax”
After setting up sensors-detect and pwmconfig, the system could control the fan speed based on the CPU temperature, to increase the fan speed when the CPU temp increased. But the fan alone is not capable of cooling the system when the CPU utilization is high.
Therefore, I wanted to confirm that there was also CPU scaling happening to reduce the amount of heat generated. From what I could see, there is no CPU scaling happening at all. There are no thermal files in /proc/acpi and the counts in /sys/devices/system/cpu/cpu*/thermal_throttle/*count are all zero always.
Here are some log messages about thermal and ACPI:
[ 0.102080] CPU0: Thermal monitoring enabled (TM1)
…
[ 0.279322] thermal LNXTHERM:00: registered as thermal_zone0
[ 0.279326] ACPI: thermal: Thermal Zone [THRM] (54 C)
and there are 4 sets of messages about ACPI ranges in conflict, here is the first one:
[ 1.054421] ACPI Warning: SystemIO range 0x0000000000000528-0x000000000000052F conflicts with OpRegion 0x0000000000000500-0x000000000000057F (\PMIO) (20230628/utaddress-204)
[ 1.054437] ACPI: OSL: Resource conflict; ACPI support missing from driver?
[ 1.054439] ACPI: OSL: Resource conflict: System may be unstable or behave erratically
The system is running MrChromebox BIOS version 2503.0 from 2025.04.27 (with the new settings menu!)
Questions:
Is this system capable of controlling CPU frequency to manage its temperature when running MrChromebox BIOS?
Do I need to fix my ACPI settings to avoid the conflict reported in the logs? Where can I look for more information to do that?
Or should I explore a different way to manage CPU frequency? such as https://github.com/intel/thermal_daemon
Thanks for your help