Auto-disabling devices to save power

In Linux, you can set different power schemes to unload modules responsible for particular hardware, say CDROM, PCMCIA port, Firewire etc.

In Windows, I can of course go to Device Manager and do it manually, BUT it would be much more desired to have it disable selected devices automatically whenever I switch from AC to Battery power.

Is there a program that enables such a thing on Windows?

 

In Windows XP, yes. You can setup hardware profiles to suit your needs. IIRC these can be automatically activated by system status (most often seen in docked/undocked configurations).

In Windows 7/Vista, not so much. Windows 7 uses device resources through vastly more efficient power states and/or consumption of device resources. If a network adapter is not being used, Windows 7 will send it to a low-power state. Once a CAT5 cable is connected, the power state will be restored to full power. Same for Bluetooth, CPU, RAM, display, etc. Of course, this does require cooperation from the hardware/OEM manufacturers. Being able to suspend the Bluetooth in your HP laptop is all well and good but ultimately useless if the Broadcom radio doesn't support a low-power mode. However, most modern components support some kind of power mode which Windows can utilize.

While the hardware profiles of Windows XP are no longer available, the power management in Windows 7 is designed to be much more intelligent, providing an optimal user experience with identical or nearly identical performance in most situations.

Here is a link to a white-paper on Power Management in Windows 7 which greatly expands on my very simple examples. It was written last year during the beta/RC development phase.

http://download.microsoft.com/downl...1677/Windows7_Power_Management_Whitepaper.pdf

--L.

 

Thank you.

Can it? I strongly doubt it as over the years of using XP, I never encountered a way to disable devices automatically.

Can you elaborate on it?

 

I am interested in learning about this possibility in XP as well.

cheers ...

 

You can, but you'll have to write your own program.
You can use devcon to turn off devices in windows.

 

The Hardware Profiles in XP do require a reboot to take effect - that was kinda automatic in 2001. Here are a couple of links to KB articles on using Hardware Profiles in XP. Note the sections about setting a default profile when you have several profiles - this enables the boot-time profile selection.

http://support.microsoft.com/kb/308577
http://www.microsoft.com/resources/...n-us/hardware_profiles_overview.mspx?mfr=true

Holy carp, I forgot about devcon. I had a Toshiba laptop with a dock which would switch profiles for me. I had a devcon script to "fix" part of the profile switching when Toshiba wouldn't - I stopped buying Toshiba after that.

That seems so long ago: my next three XP systems didn't have docks so I haven't used Hardware Profiles or devcon since.

--L.