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Milano
Asked: 2018-07-23 06:16:48 +0800 CST

CPU Frequency is allways the lowest possible (and high CPU usage)

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Recently, I've noticed that my PC is very slow (even youtube videos aren't fluent).

I have acer aspire nitro 5 and my battery is probably dead.

I thought that it's throttling because of high CPU temperatures but it isn't:

sensors

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I can see that CPU frequency is about 800.000 MHZ which is the lowest possible.

lscpu

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And as you can see the usage is very high (I started Intellij Idea)

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I tried to manually set CPU frequency to max:

sudo cpufreq-set -f `cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq`

but it returns error:

Error setting new values. Common errors: - Do you have proper administration rights? (super-user?) - Is the governor you requested available and modprobed? - Trying to set an invalid policy? - Trying to set a specific frequency, but userspace governor is not available, for example because of hardware which cannot be set to a specific frequency or because the userspace governor isn't loaded?

Do you know what should I do?

performance cpu 16.04

1 Answers

  1. Best Answer

    Dead battery

    A battery below 5% charge is a critical issue and all sorts of exceptions will be implemented by the software. This might include limiting speed until battery goes above 10-30% charge. Which in your case would never happen. You could probably pick up a used / refurbished battery fairly cheaply on eBay or Amazon.

    Set to Performance governor in cpufrequtils

    From this Ask Ubuntu answer, follow these steps:

    Edit the following file (if it doesn't exist, create it):

    sudo nano /etc/default/cpufrequtils

    And add the following line to it:

    GOVERNOR="performance"

    Save and exit.

    For changes to immediately take effect without rebooting, run:

    sudo /etc/init.d/cpufrequtils restart

    Then you can run cpufreq-info to see informations about your cpu frequency, governor and more:

    $ cpufreq-info
current policy: frequency should be within 800 MHz and 3.90 GHz.
          The governor "performance" may decide which speed to use
          within this range.

    From another answer Setting to High Performance: you can see CPU frequency differences between Powersave and Performance governors:

    Performance Mode

    In performance mode you will then notice CPU% utilization drops by about 5% but also notice speed will increase from about 1000 MHz to 3000 MHz and temperatures will spike by ~10 degree, depending on your processor:

    CPU Performance mode.gif

    Powersave mode

    CPU powersave.gif

    Switching back to powersave mode CPU% utilization has spiked by 5%, but CPU frequency has dropped by 1500 MHz and temperature has decreased by about 10 degrees. Overall powersave mode is the best for most configurations.

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