turning devices on and off to save power

[buddhaboy]

what is the best way to turn devices such as screen, cdrom, usb ports, (possibly unused bus) on and off during run time.
i would prefer a raw, straight forward method apposed to some sort of management software because i would like to control devices power status in custom services/ scripts/ bins thanks in advance!

[phenest]

Have you done any research of your own prior to asking here? If so, please share so we can help with what you found.

[pylkko]

If your question were even a tad bit more specific there could be some interesting discussion, but unfortunately, as is it is just too vague for there to be anything interesting to say. Many periferials can be turned off and others can be forced into low power states. It is also possible to estimate approximately how much power a device uses with tools like powertop

[phenest]

unfortunately, as is it is just too vague for there to be anything interesting to say.

Whilst I agree with this, I gave it some thought and some answers may be obvious given the vagueness of the question:

Modern optical drives support something called Zero Power. This basically means that when it's not in use, it automatically turns itself off so it uses no power. This is a hardware feature, and I don't think this can be accomplished via software.

As for the screen: a screensaver can deal with that.

And as for USB ports, surely if you unplug something from it, the USB port is not consuming power any more.

[Bulkley]

Code: Select all

shutdown -h now

Code: Select all

systemctl poweroff