I am using a MacBook Retina with four processor cores on Linux (Ubuntu 18.04):
$ grep -E '^model name|^cpu MHz' /proc/cpuinfo model name : Intel(R) Core(TM) i5-4258U CPU @ 2.40GHz cpu MHz : 799.976 model name : Intel(R) Core(TM) i5-4258U CPU @ 2.40GHz cpu MHz : 799.993 model name : Intel(R) Core(TM) i5-4258U CPU @ 2.40GHz cpu MHz : 799.992 model name : Intel(R) Core(TM) i5-4258U CPU @ 2.40GHz cpu MHz : 800.016
In order to enable this governor (and the on-demand one), I switched to the
acpi-cpufreq driver. Follwoing instructions at (Setting CPU governor to on demand or conservative) and (https://ubuntuforums.org/showthread.php?t=1767485), I had to enable two kernel flags in
Anyway. This is what
cpufreq-info gives me:
driver: acpi-cpufreq CPUs which run at the same hardware frequency: 3 CPUs which need to have their frequency coordinated by software: 3 maximum transition latency: 10.0 us. hardware limits: 768 MHz - 2.40 GHz available frequency steps: 2.40 GHz, 2.40 GHz, 2.30 GHz, 2.00 GHz, 1.80 GHz, 1.50 GHz, 1.30 GHz, 1.10 GHz, 900 MHz, 768 MHz available cpufreq governors: conservative, ondemand, userspace, powersave, performance, schedutil current policy: frequency should be within 768 MHz and 2.40 GHz. The governor "performance" may decide which speed to use within this range. current CPU frequency is 800 MHz.
So the 768-2400MHz hardware limits are well known, but somehow it refuses to move away from the 800MHz. I tried with ondemand with no more success.
Now here is the funny part.
If I simply use
cpupower frequency-info, I get
current CPU frequency: Unable to call hardware current CPU frequency: 800 MHz (asserted by call to kernel)
However, if I call
cpupower as root, I get
current CPU frequency: 2.40 GHz (asserted by call to hardware)
How the heck is this possible? The kernel and the hardware report different values (and it feels slow, so I'd trust the kernel). Do you have any clue as to what could be the issue here?