What power state is the system in when shutdown windows 8.1?

Question

Hi all,

I am trying to figure out what power state is the system in when windows 8.1 industry is shutdown. Is it in S3, S4 or S5 state? How do you configure the system to shutdown in each of those state? Any help is very much appreciated.

Answer 1

Hi hal_2000,

System Power States are getting complicated in Windows 8 and 10.
  With Windows 8, Connected Standby (CS) enables the smartphone power model on the PC.
  Windows 10 Modern Standby (MS) expands the Windows 8.1 Connected Standby power model ....
Refer to the below article:
  Modern Standby
  https://docs.microsoft.com/ja-jp/windows-hardware/design/device-experiences/modern-standby

Please read this:
  System Power States
  https://msdn.microsoft.com/en-us/library/windows/desktop/aa373229(v=vs.85).aspx

Regards,

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Ashidacchi

Answer 2

S0 = working.

S1~4 = half-asleep or half-awake depending on which way it is going.

S5 = shutdown.

Reference: system power states

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=^x^=

Answer 3

I understand those are the power states however I am trying to determine the state when user click the shutdown button in the Win 8.1 Industry. I have monitored the signal outputs from a COM express connector state signal at SUS_S5# which I believe corresponded to the power state S5 and I expected SUS_S5# to be low when the windows is shutdown but that signal SUS_S5# is never low at all.

So that is why I have asked the question. My understanding is that those state signal outputs are controlled by the ACPI device driver so my subsequent question is how to configure the system to force the signal SUS_S5# to low. 

Answer 4

Hi hal_2000,

I hope you will create a new thread instead of adding a subsequent question, if your first question is answered. (Adding subsequent questions make the thread endless)  

Regards,

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Ashidacchi

Answer 5

There is another forum that might help with this hardware / firmware / driver related question. I am going to move the questions there.

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Sean Liming - Book Author: Starter Guide Windows 10 IoT Enterprise - www.annabooks.com / www.seanliming.com