IEI Integration NANO-9452 v1.00 - Manual (Page 141)

NANO-9452 EPIC Motherboard
Page 123
Yes D EFAULT Enables the ACPI support for the operating system. This
selection should be enabled if the OS does support ACPI
6.3.5.1 General ACPI Configuration
Use the General ACPI Configuration menu (BIOS Menu 9) to select the ACPI state
when the system is suspended.
BIOS Menu 9: General ACPI Configuration [Advanced\ ACPI Configuration]
Suspend Mode [S1(POS)]
Use the Suspend Mode option to specify the sleep state the system enters when it is not
being used.
S1 (POS) D EFAULT The system enters S1(POS) sleep state. The system
appears off. The CPU is stopped; RAM is refreshed; the
system is running in a low power mode.