# How to check if dedicated video card is deactivated?

## candamil

Hi there, I have just installed optimus in my laptop (dell XPS15, L502X). I have done a couple of battery tests to check if it's working properly.

With the optimus service stopped, the battery lasts 2:07, and with it started, it lasts 2:27, same conditions (muted sound, wifi off, bt off, brightness to the minimum...).

It's slightly better, but I thought the difference would be bigger. 

Does anybody know if there is a way to check if the dedicated video card is deactivated or not when it's not being used?

In my case, my integrated video card is an Intel HD3000 and the dedicated one is a nvidia GT525m. 

Thank you.

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## YsndHalf

Hi,

I'm also interested in this. I have a Thinkpad T420s, with nVidia NVS 4200M, and in Gentoo the battery is lasting significantly less than in Windows 7. So maybe it's the nVidia being more active than it should be.

Thanks!

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## Jaglover

Not sure, maybe powertop can help.

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## candamil

I have been trying to get powertop working, but it shows always the same message:

```

No hay estadísticas detalladas; por favor, active la opción del núcleo

Esta opción se encuentra en la seción Kernel Debugging de menuconfig

(que corresponde a CONFIG_DEBUG_KERNEL=y en el fichero de configuración)

Nota: sólo disponible en versiones 2.6.21 y posteriores del núcleo

```

It means that I need to activate the CONFIG_DEBUG_KERNEL option to get the detailed statistics.

The problem is that that option IS activated:

```

  │ Symbol: DEBUG_KERNEL [=y]                                                                                                      │  

  │ Type  : boolean                                                                                                                │  

  │ Prompt: Kernel debugging                                                                                                       │  

  │   Defined at lib/Kconfig.debug:146                                                                                             │  

  │   Location:                                                                                                                    │  

  │     -> Kernel hacking                                                                                                          │  

  │   Selected by: EXPERT [=y]                                                                                                     │  

```

So I don't know where the problem is. Any idea?

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## candamil

Finally I was able to get it working, but unfortunately, that's not a good solution. As powertop only shows interruption frequency, if the dedicated card is not running any program, it won't be in the list of powertop. 

I think we need to find another option.

Thank you anyway.

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