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Windows 2008 R2 USB device "allow the computer to turn off this device to save power"

    Question

  • there is an option "allow the computer to turn off this device to save power" in property of USB device such as generic USB hub. Is it the same as disabling USB selective suspend if I uncheck all USB devices "allow the computer to turn off this device to save power"?
    Thursday, July 07, 2011 6:03 AM

Answers

  • The USB selective suspend feature allows the hub driver to suspend an individual port without affecting the operation of the other ports on the hub. Selective suspension of USB devices is especially useful in portable computers, since it helps conserve battery power. Many devices, such as fingerprint readers and other kinds of biometric scanners, only require power intermittently. Suspending such devices, when the device is not in use, reduces overall power consumption.

     

     Article ID: 930312 - The "Allow the computer to turn off this device to save power" power management option for a USB Root Hub does not remain selected after you restart Windows Vista

     

    Looking at the KB, it seems both the settings have the same effect.

     

     


    Sumesh P - Microsoft Online Community Support
    Monday, July 11, 2011 4:20 PM
  • If you want to manage the setting via registry, you can paste the following in notepad and save as a .reg file and import or create the keys manually.



    Windows Registry Editor Version 5.00

    [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\USB]
    "DisableSelectiveSuspend"=dword:00000001

     

     


    Sumesh P - Microsoft Online Community Support
    Wednesday, July 13, 2011 4:54 PM
  • DisableSelectiveSuspend (DSS) is a global key which applies the policy to all USB Hubs and devices. Setting each device individually can accomplish a similar task but it’s not exactly the same. If a user plugs in any new device and wants to manually decide to allow OS control or not, enabling DSS removes "allow the computer to turn off this device to save power"  option from the UI.  By default the global key is set to allow selective suspend so the OS can efficiently control  power savings. Enabling DSS or manually tweaking all devices would result in a potential for more power consumption which is not a good thing for battery life on laptops. Manually setting each device would require the end user to tweak the setting for all hubs and new devices as they are attached to maintain their preferences. Another key difference, manually disabling a hub from going into selective sleep would not prevent any attached hubs and/or devices down chain to be affected by the policy.  Manual method works best for a noncompliant USB hub or devices that does not handle selective suspend states well. Majority of users leave the global key alone and only tweak a device that is not spec compliant or device that needs to be up 100% of the time.

     

    Win7 and Win2008 R2 has the same behavior.


    Sumesh P - Microsoft Online Community Support
    Wednesday, July 13, 2011 4:55 PM

All replies

  • The USB selective suspend feature allows the hub driver to suspend an individual port without affecting the operation of the other ports on the hub. Selective suspension of USB devices is especially useful in portable computers, since it helps conserve battery power. Many devices, such as fingerprint readers and other kinds of biometric scanners, only require power intermittently. Suspending such devices, when the device is not in use, reduces overall power consumption.

     

     Article ID: 930312 - The "Allow the computer to turn off this device to save power" power management option for a USB Root Hub does not remain selected after you restart Windows Vista

     

    Looking at the KB, it seems both the settings have the same effect.

     

     


    Sumesh P - Microsoft Online Community Support
    Monday, July 11, 2011 4:20 PM
  • thank you. it's helpful.

    i checked article ID 314634 but cannot find the registry HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\USB in windows 2008. Which registry should I edit?

    thanks

    Tuesday, July 12, 2011 3:05 AM
  • You can do it via the GUI, in the Power Options dialog box, expand USB settings, and then expand USB selective suspend setting and set it to disabled.


    Sumesh P - Microsoft Online Community Support
    Wednesday, July 13, 2011 10:59 AM
  • If you want to manage the setting via registry, you can paste the following in notepad and save as a .reg file and import or create the keys manually.



    Windows Registry Editor Version 5.00

    [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\USB]
    "DisableSelectiveSuspend"=dword:00000001

     

     


    Sumesh P - Microsoft Online Community Support
    Wednesday, July 13, 2011 4:54 PM
  • DisableSelectiveSuspend (DSS) is a global key which applies the policy to all USB Hubs and devices. Setting each device individually can accomplish a similar task but it’s not exactly the same. If a user plugs in any new device and wants to manually decide to allow OS control or not, enabling DSS removes "allow the computer to turn off this device to save power"  option from the UI.  By default the global key is set to allow selective suspend so the OS can efficiently control  power savings. Enabling DSS or manually tweaking all devices would result in a potential for more power consumption which is not a good thing for battery life on laptops. Manually setting each device would require the end user to tweak the setting for all hubs and new devices as they are attached to maintain their preferences. Another key difference, manually disabling a hub from going into selective sleep would not prevent any attached hubs and/or devices down chain to be affected by the policy.  Manual method works best for a noncompliant USB hub or devices that does not handle selective suspend states well. Majority of users leave the global key alone and only tweak a device that is not spec compliant or device that needs to be up 100% of the time.

     

    Win7 and Win2008 R2 has the same behavior.


    Sumesh P - Microsoft Online Community Support
    Wednesday, July 13, 2011 4:55 PM
  • it's clear. thank you so much.
    Thursday, July 14, 2011 1:32 AM