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domingo

Member

Registered: 2023-06-08

Posts: 10

Intel i7 Macbook CPU throttled to min. speed

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

Last edited by domingo (2023-06-08 19:11:04)

jl2

Member

From: 47° 18' N 8° 34' E

Registered: 2022-06-01

Posts: 1,214

Re: Intel i7 Macbook CPU throttled to min. speed

Running Manjaro 23

These are Arch only forums

have you tried https://wiki.archlinux.org/title/CPU_fr … limitation?
be careful not to fry your cpu:

TJUNCTION 100 C

https://ark.intel.com/content/www/de/de … 0-ghz.html

---

Why I run Arch? To "BTW I run Arch" the guy one grade younger.
And to let my siblings and cousins laugh at Arsch Linux...

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domingo

Member

Registered: 2023-06-08

Posts: 10

Re: Intel i7 Macbook CPU throttled to min. speed

I'm sorry for the OS confusion. I was using Arch before I still feel there, although didn't have the time lately to install it from scratch. I should do it again soon, but not sure this problem will be gone.

I tried changing ignore_ppc to 1 (ignore BIOS limitation), but the problem still happens. This time at only 72° supposedly. I'm puzzled, but appreciate your suggestion @jl2!