# An hour less of battery life on and off intel_pstate?

## MarioMaster100

I was on battery life with the intel_pstate enabled on the laptop and I had at least an hour of battery life or more less that I should have. Then I recompiled the kernel without the intel_pstate driver and the battery life looked about the same. Any tips or tricks to get that battery life back up to where it should be?

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## toralf

Maybe OT, but do you want to play with the pstate or just want to save power? B/C there are well established other alternatives in the kernel IMO, eg. ondemand is a stable and working governor.

And the last time I looked at pstate it was flaky and buggy and not usable here at a x86 Gentoo at a ThinkPad (with just internal i915 graphic).

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## MarioMaster100

Whatever works best is what I'm going with  :Smile:  Currently I have the pstate not on the kernel, need to figure out how to set the default governor.

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## john_deaux

You can set the default governor here:

```
CPU Frequency scaling  --->

    Default CPUFreq governor (performance)

    <*> 'performance' governor

    x86 CPU frequency scaling drivers  --->

      [*] Intel P state control
```

j_d

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## shazeal

 *Quote:*   

>  CONFIG_X86_INTEL_PSTATE:                                                                                      │  
> 
>   │                                                                                                               │  
> 
>   │ This driver provides a P state for Intel core processors.                                                     │  
> ...

 

Do you have a Sandy bridge cpu?

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## MarioMaster100

 *shazeal wrote:*   

>  *Quote:*    CONFIG_X86_INTEL_PSTATE:                                                                                      │  
> 
>   │                                                                                                               │  
> 
>   │ This driver provides a P state for Intel core processors.                                                     │  
> ...

 

I believe so.

 *john_deaux wrote:*   

> You can set the default governor here:
> 
> ```
> CPU Frequency scaling  --->
> 
> ...

 Ok, is that the only location to manually set it?

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## john_deaux

 *MarioMaster100 wrote:*   

>  *shazeal wrote:*    *Quote:*    CONFIG_X86_INTEL_PSTATE:                                                                                      │  
> 
>   │                                                                                                               │  
> 
>   │ This driver provides a P state for Intel core processors.                                                     │  
> ...

 

Not sure, I set mine to performance in the kernel.  I think the default was "powersave" or something like that.

You can easily modify the kernel to change this.

j_d

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## MarioMaster100

I think I forgot to set cpupower to powersave when I took off intel_pstate, looks about right with pstate not in the kernel and powersave governor >_< Maybe I'll check with intel_pstate again and set the cpu governor and see.

Edit: nope problem not solvedLast edited by MarioMaster100 on Wed Jul 30, 2014 11:07 pm; edited 1 time in total

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## MarioMaster100

Alright I don't know what to believe anymore. I'm starting to think battery_time for conky is wildly inaccurate... Is there a more accurate way to measure battery time remaining preferably a conky method that I can just add a variable to my dzen2 script?

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## MarioMaster100

Well both conky and acpi are flipping battery life remaining a bit more than they should be...

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