Intel vPro Processor Technology Setup and Configuration for the HP Z1, Z210, Z420, Z620 and Z820 Workstations

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Appendix B: Power / Sleep / Global States
Explained
Under Advanced Configuration and Power Interface (ACPI) specification a PC can
be in one of several Power states. These power states are also known as Sleep (Sx)
states or Global (Gx) states.
S0 is the ON state. The PC is fully functioning. All system devices and operating
system, if available, are running. S0 is also known as G0.
S3 is the Standby (Microsoft terminology) or Suspend-to-RAM state. The memory
subsystem and V
aux
power rail remains powered, while the rest of the system
including the processor are not powered. When the system resumes from S3, the
system context remains intact because the system memory was preserved and
powered at all times.
S4 is the Hibernate (Microsoft terminology) or Suspend-to-Disk state. The system
context (memory) is saved to the hard drive as a hibernation file. When the system
resumes from S4, the system context is restored from the hibernation file. V
aux
remains powered, but all other subsystems including system memory and the
processor are not powered.
S5 is the Soft Off state. It is identical to S4 with the exception that the system
context is not saved. When the system resumes from S5, it will power up and
going through POST. S5 is also known as G2.
G3 is the Mechanical Off state. All subsystems are not powered in this state. The
easiest way to achieve this state is by removing A/C power from the system via
unplugging the power cord.
The ME has its own power states (Mx) similar to the Sx states.
M0 is the ON state for the ME when the system is in S0 state. The ME is fully
powered and running.
M3 is the ON state for the ME when the system is in a non-S0 state. The ME is
fully powered and running.
Moff is the OFF state for the ME. The system is in a non-S0 state.
The ME can be set to stay powered and active in all Sx states. If the system (host) is
in S0, then the ME will be in the corresponding M0 state. However, if the system is
in S3, S4, or S5, then the ME will still remain active, but it will be in M3 state.