# [SOLVED] i7 Powersave, Frequency Scaling and Etc

## Holysword

I used to be a happy user of ACPI and cpufreqd

But then I got a new computer

```
Linux jarvis 3.15.3-gentoo #4 SMP PREEMPT Wed Jul 9 15:44:41 PDT 2014 x86_64 Intel(R) Core(TM) i7-4700MQ CPU @ 2.40GHz GenuineIntel GNU/Linux
```

together with a tsunami of warnings on how those things were deprecated and not suitable for my hardware. Then I tried to install the P_States modules but... nothing works.

Currently my governor is hardcore set to performance. I seem to be unable to change the frequency using cpupower. For instance:

```
◢ jarvis ◣ linux $  cpupower frequency-set -f 800

Setting cpu: 0

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?

◢ jarvis ◣ linux $  cpupower info

System's multi core scheduler setting: not supported

System's thread sibling scheduler setting: not supported

analyzing CPU 0:

Could not read perf-bias value

◢ jarvis ◣ linux $
```

Naturally all modules exist and are loaded... I just don't think that P_States cares about them. This is really annoying because my  gadgets (I use E18) seem to be unable to control the frequency of the processor and I am unable to control it via command line. Sometimes my laptop is idle (i.e. I am having shower) and I come back and I could literally fry an egg on it. I am really sure that whatever this is doing, its doing wrong.

But the worse of them all is that the wiki seems to be ridiculously outdated. I couldn't find much help around, unless it involved at least 6 pages of deep knowledge on SandyBridge architecture. Could anyone point me out a "for newbies" guide on this thing?

Here is my .config file just in case:

http://pastebin.com/XhqXzeAw

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## Roman_Gruber

I do this as user root below!

As far as i know i usually write this

cpupower frequency-set -f 1200000

you need to write the full herz not the megaherz. So in my example 1.2GHZ equals 1200000

or when you want to set the governor to ondemand

cpupower frequency-set -g ondemand

there is also performance / powersave ... but that depends on your kernel config and build kernel.

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## loki_val

With the newer Intel processors such as yours, the manual cpufreq setting is NOT relevant. It should be throttling down automatically if it's using the ondemand governor. What you're doing now is probably causing it to always run it at a specific frequency, which is not what you want. Intel CPUs nowadays dynamically scale up and down their performance depending on the load. When you've got the ondemand governor setup, you should take a look at the powertop tool to get the last bit of juice out of your battery. It also has a tab for enabling additional powersaving functions that may have been not enabled because... Reasons. 

The best guide googling turned up which agrees with how I remember things last I dived into this is the Arch Linux one at

https://wiki.archlinux.org/index.php/CPU_frequency_scaling

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## Holysword

 *loki_val wrote:*   

> With the newer Intel processors such as yours, the manual cpufreq setting is NOT relevant. It should be throttling down automatically if it's using the ondemand governor. What you're doing now is probably causing it to always run it at a specific frequency, which is not what you want. Intel CPUs nowadays dynamically scale up and down their performance depending on the load. When you've got the ondemand governor setup, you should take a look at the powertop tool to get the last bit of juice out of your battery. It also has a tab for enabling additional powersaving functions that may have been not enabled because... Reasons. 
> 
> The best guide googling turned up which agrees with how I remember things last I dived into this is the Arch Linux one at
> 
> https://wiki.archlinux.org/index.php/CPU_frequency_scaling

 

Thank you very much and sorry for the delay in replying.

Its good to know then.  I will keep it on ondemand. I have turned off several ACPI options in my kernel because it was causing weird behaviour with my mouse - for some reason it would send it to rest after about 20s of inactivity, and it was quite annoying having to shake it for a while to get the control back. It was just the mouse though.

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