How can I tell Windows or Linux to power a specific device (e.g. USB controller, network card, video card) down, that is put it in the D3 state? From the very little I know about ACPI and such, the operating system has control over this, as it puts devices in said D3 state (if supported) for example when putting the computer into sleep (S3) mode. I am wondering if there is a way to do this manually for certain devices.
For Linux I found this thread, suggesting enabling the driver to control the power of the device using e.g.
echo -n "auto" > /devices/pci0000:00/0000:00:02.0/power/control'
and then unloading the driver:
echo -n "0000:00:02.0" > /sys/bus/pci/drivers/i915/unbind
so that the device will sleep.
Is there another way? Perhaps to emulate what happens when the whole system is put to sleep mode?
Additionally, how would this work in Windows 7?