CPU frequency is always at minimum, even if CPU usage is 100%

Solution 1:

It turned out that this problem was unrelated to the intel_pstate driver, because acpi_cpufreq, the other driver, reported better values but never set them. The OS had probably no control over this.

This is a issue that happens with certain Dell laptops when charging is broken in a way that the laptop is powered by AC but not charged. Fixing the hardware problem removes the problem. In this case, it was an almost invisible piece of cloth in the power connector that prevented electrical contact.

Solution 2:

Sometimes my laptop completely ignores the cpufreq settings. I found this works:

Unplug the power cord and plug it back in again. Fixed :)

I am guessing the reason is that the machine got confused: it thinks it is on battery, and it thinks the battery is low, so it underclocks the CPU to save power.

We just need to let it know that it is actually plugged in and doing fine.

(Asus x453m laptop here, Ubuntu 14.04) YouTube: Have you tried turning it off and on again?

Solution 3:

This will set your cpu freq to top speed from any terminal:

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

Edit the /etc/init.d/ondemand file to permanently add this. ondemand is used to modify your freq during login. The default is the 'ondemand' governor. In other words you start at 800mhz and go up as needed.

Solution 4:

I had the same issue - cpu freq stuck in ubuntu as well as windows, after a overheated shutdown in the carry case with the laptop still being on.

I went to the BIOS, and disabled cpu power management in "power", and put everything else to full throttle (max performance). Rebooted, back to full speed, then back to the BIOS, and enabled cpu management again, and corrected the other settings I changed before. Et voilà!

EDIT: Turns out it is a battery issue. If the battery is really low, the cpu won't speed up (I assume to save power). On my thinkpad I have to charge the battery for some minutes, until the charging LED stops fast flickering BEFORE I turn on the machine again.

Solution 5:

I ended up here because I had a similar problem. On my laptop with an Intel Core i5-6267U, the CPU would get stuck at the minimum frequency of 400 MHz, although it turned out that sometimes it could return to higher frequencies. Specifically, frequencies returned to normal after reboot or going to sleep. However, it would quickly get stuck at 400 MHz again.

Turns out, the fan was broken and when the CPU became too hot, it went into some kind of safe mode that it did not leave when the CPU cooled down again. That was what initially confused me: The CPU would be at low temps, but stuck at minimum clock. So it was not strange that the fan was not running because it should not be at those temps.

What led me to solution was that I put the CPU under heavy load with a video transcode. There I could see the CPU quickly getting hotter and then throttling to 400 MHz when it got it 85°C or so. The fan never turned on.

I ordered a new fan for the laptop and now its working perfectly fine.