Тормоза при работе от внешней батареи

[AntonKuzmin]

Доброго времени суток. Столкнулся со странной проблемой. Есть ноут Dell XPS 9550 и внешняя батарея Dell Power Companion 12000mAh PW7015M.
На странице батареи указана совместимость с данным ноутом. При её подключении бук со временем начинает сильно тупить. Чем больше времени проходит тем сильнее становятся тормоза.
Может ли в этом быть виновата ОС/ядро? Стоит Debian 9 (Linux ws 4.9.0-1-amd64 #1 SMP Debian 4.9.6-3 (2017-01-28) x86_64 GNU/Linux).
Может это какое-то особое понижение частоты CPU в эконом-режиме который сам как-то включается автоматически?

Погуглив на тему тормозов у лаптопов делл при батарее на Linux, набрёл на команду cpufreq-info. Вот такой у неё вывод если я работаю с подключенной сетью:

Открыть содержимое (спойлер)

analyzing CPU 0:
  driver: intel_pstate
  CPUs which run at the same hardware frequency: 0
  CPUs which need to have their frequency coordinated by software: 0
  maximum transition latency: 0.97 ms.
  hardware limits: 800 MHz - 3.20 GHz
  available cpufreq governors: performance, powersave
  current policy: frequency should be within 800 MHz and 3.20 GHz.
                  The governor "powersave" may decide which speed to use
                  within this range.
  current CPU frequency is 800 MHz (asserted by call to hardware).
analyzing CPU 1:
  driver: intel_pstate
  CPUs which run at the same hardware frequency: 1
  CPUs which need to have their frequency coordinated by software: 1
  maximum transition latency: 0.97 ms.
  hardware limits: 800 MHz - 3.20 GHz
  available cpufreq governors: performance, powersave
  current policy: frequency should be within 800 MHz and 3.20 GHz.
                  The governor "powersave" may decide which speed to use
                  within this range.
  current CPU frequency is 816 MHz (asserted by call to hardware).
analyzing CPU 2:
  driver: intel_pstate
  CPUs which run at the same hardware frequency: 2
  CPUs which need to have their frequency coordinated by software: 2
  maximum transition latency: 0.97 ms.
  hardware limits: 800 MHz - 3.20 GHz
  available cpufreq governors: performance, powersave
  current policy: frequency should be within 800 MHz and 3.20 GHz.
                  The governor "powersave" may decide which speed to use
                  within this range.
  current CPU frequency is 800 MHz (asserted by call to hardware).
analyzing CPU 3:
  driver: intel_pstate
  CPUs which run at the same hardware frequency: 3
  CPUs which need to have their frequency coordinated by software: 3
  maximum transition latency: 0.97 ms.
  hardware limits: 800 MHz - 3.20 GHz
  available cpufreq governors: performance, powersave
  current policy: frequency should be within 800 MHz and 3.20 GHz.
                  The governor "powersave" may decide which speed to use
                  within this range.
  current CPU frequency is 800 MHz (asserted by call to hardware).

[свернуть]

Отключаю сеть:

Открыть содержимое (спойлер)

analyzing CPU 0:
  driver: intel_pstate
  CPUs which run at the same hardware frequency: 0
  CPUs which need to have their frequency coordinated by software: 0
  maximum transition latency: 0.97 ms.
  hardware limits: 800 MHz - 3.20 GHz
  available cpufreq governors: performance, powersave
  current policy: frequency should be within 800 MHz and 3.20 GHz.
                  The governor "powersave" may decide which speed to use
                  within this range.
  current CPU frequency is 800 MHz (asserted by call to hardware).
analyzing CPU 1:
  driver: intel_pstate
  CPUs which run at the same hardware frequency: 1
  CPUs which need to have their frequency coordinated by software: 1
  maximum transition latency: 0.97 ms.
  hardware limits: 800 MHz - 3.20 GHz
  available cpufreq governors: performance, powersave
  current policy: frequency should be within 800 MHz and 3.20 GHz.
                  The governor "powersave" may decide which speed to use
                  within this range.
  current CPU frequency is 800 MHz (asserted by call to hardware).
analyzing CPU 2:
  driver: intel_pstate
  CPUs which run at the same hardware frequency: 2
  CPUs which need to have their frequency coordinated by software: 2
  maximum transition latency: 0.97 ms.
  hardware limits: 800 MHz - 3.20 GHz
  available cpufreq governors: performance, powersave
  current policy: frequency should be within 800 MHz and 3.20 GHz.
                  The governor "powersave" may decide which speed to use
                  within this range.
  current CPU frequency is 800 MHz (asserted by call to hardware).
analyzing CPU 3:
  driver: intel_pstate
  CPUs which run at the same hardware frequency: 3
  CPUs which need to have their frequency coordinated by software: 3
  maximum transition latency: 0.97 ms.
  hardware limits: 800 MHz - 3.20 GHz
  available cpufreq governors: performance, powersave
  current policy: frequency should be within 800 MHz and 3.20 GHz.
                  The governor "powersave" may decide which speed to use
                  within this range.
  current CPU frequency is 800 MHz (asserted by call to hardware).

[свернуть]

Подключаю внешний аккумулятор:

Открыть содержимое (спойлер)

analyzing CPU 0:
  driver: intel_pstate
  CPUs which run at the same hardware frequency: 0
  CPUs which need to have their frequency coordinated by software: 0
  maximum transition latency: 0.97 ms.
  hardware limits: 800 MHz - 3.20 GHz
  available cpufreq governors: performance, powersave
  current policy: frequency should be within 800 MHz and 3.20 GHz.
                  The governor "powersave" may decide which speed to use
                  within this range.
  current CPU frequency is 140 MHz (asserted by call to hardware).
analyzing CPU 1:
  driver: intel_pstate
  CPUs which run at the same hardware frequency: 1
  CPUs which need to have their frequency coordinated by software: 1
  maximum transition latency: 0.97 ms.
  hardware limits: 800 MHz - 3.20 GHz
  available cpufreq governors: performance, powersave
  current policy: frequency should be within 800 MHz and 3.20 GHz.
                  The governor "powersave" may decide which speed to use
                  within this range.
  current CPU frequency is 139 MHz (asserted by call to hardware).
analyzing CPU 2:
  driver: intel_pstate
  CPUs which run at the same hardware frequency: 2
  CPUs which need to have their frequency coordinated by software: 2
  maximum transition latency: 0.97 ms.
  hardware limits: 800 MHz - 3.20 GHz
  available cpufreq governors: performance, powersave
  current policy: frequency should be within 800 MHz and 3.20 GHz.
                  The governor "powersave" may decide which speed to use
                  within this range.
  current CPU frequency is 139 MHz (asserted by call to hardware).
analyzing CPU 3:
  driver: intel_pstate
  CPUs which run at the same hardware frequency: 3
  CPUs which need to have their frequency coordinated by software: 3
  maximum transition latency: 0.97 ms.
  hardware limits: 800 MHz - 3.20 GHz
  available cpufreq governors: performance, powersave
  current policy: frequency should be within 800 MHz and 3.20 GHz.
                  The governor "powersave" may decide which speed to use
                  within this range.
  current CPU frequency is 139 MHz (asserted by call to hardware).

[свернуть]

Я не особо силён в этих выводах, но падение строки "current CPU frequency" с 800mHz до 140mHz сразу бросается в глаза.
Можно ли как-то такую просадку отключать на уровне ОС и оно ли это вообще?

P.S. Опция processor.ignore_ppc=1 как-то относится к этой теме?

Update:
Ответ от делла "The Power Companion PW7015M/PW7015L .... is simply a battery charging device. It is compatible in the sense that it can charge the XPS 15-9550." и далее описывается кейс - выключить лаптоп, подключить ПБ, дождаться окончания зарядки, включить лаптоп.
Может в том и дело, что ноут понижает работоспособность чтоб побыстрее зарядить батарею и всё? И полноценная работа при подцепленном ПБ просто непредусмотрена ибо не для того девайс.

[yoric]

Да, странный случай, чтобы частота до 140 МГц падала. Просто небывалый в наше время)) Все Ваши догадки имеют право быть, разбирайтесь и пробуйте.

[serchik]

Обратите внимание на следующие статьи:
https://wiki.debian.org/HowTo/CpuFrequencyScaling
https://wiki.archlinux.org/index.php/CPU_frequency_scaling