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For each phase of the hardware system, all devices above it must enter their DRIPS.
For example, the integrated CPU cannot enter DRIPS if the chipset BUS controller is
not able to enter DRIPS.
NOTE: It is important to understand that externally connected devices may block the
system from entering the lowest power state possible.
Microsoft has created additional driver frameworks to increased support for devices
to enter DRIPS in a dynamic and intelligent manner. This is performed through the
introduction of Directed Power Management (https://docs.microsoft.com/en-
us/windows-hardware/design/device-experiences/directed-power-management).
Microsoft mandates that all certified devices and device drivers must support the
Windows Power Management Framework (PoFx) for Component Level Power
Management. Support and registration of input into this includes:
• D-state support
• Transition Latency
• Residency requirements for transitions
• Nominal power assumed to be consumed
POFX driver samples are available at https://github.com/Microsoft/Windows-driver-
samples/tree/master/pofx
All devices must support appropriate device-specific power functions to react based
on Windows commands. Windows details this as the Runtime Power Management
framework which mandates the power state that the device shall enter.
Devices outside of internal chipset (add in devices)
Network and Radio devices and interfaces
On chipset BUS controllers (USB, etc)
Integrated CPUs and GPUs
Internal logical
components of
Chipset