[SOLVED]Can't control CPU frequency properly

tacchinotacchi · 2014-08-20 02:41:37

Hi all, I am switching from Ubuntu to Arch. I can't control CPU frequency properly. I have an i7 3630qm. I searched a lot, but i couldn't find anything. What I mean is that, on Ubuntu, I had a tool called cpufreq if i remember right, in wich i could select 4 automatic cpu governors + set exact frequency if it was under 2.4, or set turbo (2.4 or more depending on work). I found that the equivalent in Arch is cpupower, but it doesn't work. Both with intel_pstate and old driver (if i remember right it's called acpi_cpufreq ). They actually have some difference, intel_pstate has less governors but recognizes turbo frequencies. The bad thing is that none of them lets me set the exact frequency: userspace governor doesn't work, setting frequency doesn't work, setting max and min frequency doesn't work even with other governors. I am really sorry I can't show specific errors, but that's not my fault, the fact is that cpupower is just giving a general error. Is there any tool that I could find usefull? Thanks in advance!

EDIT: I solved. For everyone experiencing similar issues, I disabled intel_pstate adding

intel_pstate=disable

to GRUB_CMDLINE_LINUX_DEFAULT in /etc/default/grub . What I didn't get is that maximum and minimum frequencies works only with ondemand. Also acpi_cpufreq supports Intel Turbo Boost, even if it's unable to detect Turbo Frequencies, you can still decide wether turbo is on or off:

1. You have to set the governor on userspace or ondemand;
2. Simply set a Turbo frequency to enable Turbo or set a non-Turbo freqeuncy (for me, it's less than 2.4 GHz) to disable it.

Last edited by tacchinotacchi (2014-08-20 10:41:38)

Pse · 2014-08-20 04:53:08

Did you manually disable the Intel p-state driver by setting the following in your kernel command-line?

intel_pstate=disable

WonderWoofy · 2014-08-20 04:57:45

Unless you are having problems with the pstate driver, it is probably recommended that you use it. I know there are still some corner cases where the pstate driver has caused issues, but for the most part it is a solid frequency/c-state governor that is tailor made for Intel Sandy Bridge and newer processors.

tacchinotacchi · 2014-08-20 10:02:11

Pse wrote:

Did you manually disable the Intel p-state driver by setting the following in your kernel command-line?
intel_pstate=disable

Yes I did.

WonderWoofy wrote:

Unless you are having problems with the pstate driver, it is probably recommended that you use it. I know there are still some corner cases where the pstate driver has caused issues, but for the most part it is a solid frequency/c-state governor that is tailor made for Intel Sandy Bridge and newer processors.

While both doesn't seem to support userspace (it's strange though, it worked on acpi_cpufreq on ubuntu), intel_pstate drains the whole battery in 40 mins vs 3 hours for cpufreq, and also te temp is a lot hotter with intel_pstate.

tacchinotacchi · 2014-08-20 10:35:16

I solved the error. Going to edit the first post soon. Thanks anyway

WonderWoofy · 2014-08-21 05:01:31

tacchinotacchi wrote:

...intel_pstate drains the whole battery in 40 mins vs 3 hours for cpufreq, and also te temp is a lot hotter with intel_pstate.

I would say this is one of those edge cases that would justify turning off intel_pstate. But apparently ondemand has seen some major improvements in the past few months. So either way you should be fine.

Glad you got things working properly. Forty minutes of battery time is indeed not cool.

Arch Linux

#1 2014-08-20 02:41:37

[SOLVED]Can't control CPU frequency properly

#2 2014-08-20 04:53:08

Re: [SOLVED]Can't control CPU frequency properly

#3 2014-08-20 04:57:45

Re: [SOLVED]Can't control CPU frequency properly

#4 2014-08-20 10:02:11

Re: [SOLVED]Can't control CPU frequency properly

#5 2014-08-20 10:35:16

Re: [SOLVED]Can't control CPU frequency properly

#6 2014-08-21 05:01:31

Re: [SOLVED]Can't control CPU frequency properly

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