Intel i7 Macbook CPU throttled to min. speed

Support
1

Hi,
Recently my laptop is getting stuck at minimum CPU speed (798MHz). I don’t know what is calling the action, but it happens each time the CPU is somewhat pushed to a heavy load for a while.
I was suspicious of a recent update, maybe changes on applesmc or coresmc. But I tried few different kernels and the same happens. This is a Macbook Pro 2015 i7 2.8Ghz. Running Manjaro 23.

Greasing again CPU and GPU with thermal paste didn’t help either.

After manually setting max. speed to 1.6GHz with cpupower, this is the initial info I get.

$cpupower frequency-info

driver: intel_cpufreq
CPUs which run at the same hardware frequency: 3
CPUs which need to have their frequency coordinated by software: 3
maximum transition latency: 20.0 us
hardware limits: 800 MHz - 3.70 GHz
available cpufreq governors: conservative ondemand userspace powersave performance schedutil
current policy: frequency should be within 800 MHz and 1.60 GHz.
The governor “performance” may decide which speed to use
within this range.
current CPU frequency: Unable to call hardware
current CPU frequency: 1.60 GHz (asserted by call to kernel)
boost state support:
Supported: yes
Active: yes

Five minutes later, while playback on a video editor, the mysterious throttle happens. Max. measured temperature at the moment (psensor) was is 74°C (GPU).

analyzing CPU 5:
driver: intel_cpufreq
CPUs which run at the same hardware frequency: 5
CPUs which need to have their frequency coordinated by software: 5
maximum transition latency: 20.0 us
hardware limits: 800 MHz - 3.70 GHz
available cpufreq governors: conservative ondemand userspace powersave performance schedutil
current policy: frequency should be within 800 MHz and 3.70 GHz.
The governor “performance” may decide which speed to use
within this range.
current CPU frequency: Unable to call hardware
current CPU frequency: 798 MHz (asserted by call to kernel)
boost state support:
Supported: yes
Active: yes

Only a reboot is taking it out from there.

The journal doesn’t show any events when the throttle happens, unless I am missing some parameters.
Setting cpupower to a min. speed of 1.6GHz will not prevent it from throttling down to 798MHz anyways.

If I shutdown the computer the fans start blowing at max. speed, until cooling down. So my interpretation is that the temp readings are not accurate, which makes fans not blow enough, and the CPU is self-triggering a throttle to protect itself. But I hope it’s something simpler.

Any ideas on how to diagnose this? Any information or test commands will be of enormous help.

Thanks for reading,
–Domingo

2

lm_sensors check I suppose ?

3

This is the output of lm-sensors right at the moment when CPU speed falls down to 798MHz. Max. CPU temp was 68°C, while GPU 74°C. Is this particularly hot?
I’m running now with ignore_ppc in grub, /sys/module/processor/parameters/ignore_ppc showing ‘1’ value persistently. So it doesn’t make sense the Bios is sending the signal, right?

mpbfan is installed and running but fans are idle most of the time.

radeon-pci-0100
Adapter: PCI adapter
temp1: +74.0°C (crit = +120.0°C, hyst = +90.0°C)

BAT0-acpi-0
Adapter: ACPI interface
in0: 13.02 V
temp: +38.4°C
curr1: 1.69 A (avg = +1.70 A)

pch_haswell-virtual-0
Adapter: Virtual device
temp1: +59.0°C

applesmc-isa-0300
Adapter: ISA adapter
Left side : 2458 RPM (min = 2160 RPM, max = 6156 RPM)
Right side : 2272 RPM (min = 2000 RPM, max = 5700 RPM)
TB0T: +38.0°C
TB1T: +38.0°C
TB2T: +37.8°C
TBXT: +38.0°C
TC0E: +68.2°C
TC0F: +69.5°C
TC0P: +59.8°C
TC1C: +69.0°C
TC1F: +69.2°C
TC1f: +69.2°C
TC2C: +65.0°C
TC3C: +68.0°C
TC4C: +66.0°C
TCGC: +68.0°C
TCMc: +0.0°C
TCSA: +68.0°C
TCTD: -0.2°C
TCXC: +68.5°C
TCXM: +0.0°C
TCXP: +68.5°C
TG0D: +65.2°C
TG0F: +64.8°C
TG0P: +63.0°C
TG1D: -127.0°C
TH0A: +57.0°C
TH0B: +54.0°C
TH0C: +47.2°C
TH0F: -35.0°C
TH0R: -35.0°C
TH0V: +50.8°C
TH0a: +57.0°C
TH0b: +54.0°C
TH0c: +47.2°C
TH0x: -127.0°C
TM0P: +54.2°C
TM0S: +53.2°C
TP0P: +54.0°C
TPCD: +59.0°C
TW0P: +49.8°C
Ta0P: +48.0°C
TaSP: +47.0°C
Th1H: +52.2°C
Th2H: +57.2°C
Ts0P: +35.5°C
Ts0S: +46.0°C
Ts1P: +35.0°C
Ts1S: +47.5°C

BAT0-virtual-0
Adapter: Virtual device
temp1: +38.4°C

coretemp-isa-0000
Adapter: ISA adapter
Package id 0: +68.0°C (high = +84.0°C, crit = +100.0°C)
Core 0: +68.0°C (high = +84.0°C, crit = +100.0°C)
Core 1: +65.0°C (high = +84.0°C, crit = +100.0°C)
Core 2: +66.0°C (high = +84.0°C, crit = +100.0°C)
Core 3: +66.0°C (high = +84.0°C, crit = +100.0°C)