# Surface Pro 4 Power Tuning

## Audio

[Idle audio card](https://wiki.archlinux.org/index.php/Power_management#Audio) after one second:

```shell
echo "options snd_hda_intel power_save=1" > /etc/modprobe.d/audio_powersave.conf
```

## Kernel Tuning

[Disable NMI watchdog](https://wiki.archlinux.org/index.php/Power_management#Disabling_NMI_watchdog). It can generate a lot of interrupts, causing a noticeable increase in power usage.

```shell
echo "kernel.nmi_watchdog = 0" > /etc/sysctl.d/disable_watchdog.conf
```

## PCI

Enable [PCI Runtime Power Management](https://wiki.archlinux.org/index.php/Power_management#PCI_Runtime_Power_Management)

```shell
echo "ACTION=="add", SUBSYSTEM=="pci", ATTR{power/control}="auto"" > /etc/udev/rules.d/pci_pm.rules
```

## References

* [Arch Wiki](https://wiki.archlinux.org)
  * [Powertop](https://wiki.archlinux.org/index.php/Powertop)
  * [Power Management](https://wiki.archlinux.org/index.php/Power_management#Power_management_with_systemd)