Dell PowerEdge T20 User Manual

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CAUTION: All other components on the motherboard will lose data once power is removed from the system. Primary

power loss (Unplug the power cord and remove the battery) will destroy all user data on the memory (DDR3, 1600MHz).
Secondary power loss (removing the on board coin-cell battery) will destroy system data on the system configuration and
time-of-day information.

In addition, to clarify memory volatility and data retention in situations where the system is put in different ACPI power
states the following is provided (those ACPI power states are S0, S1, S3, S4 and S5):

• S0 state is the working state where the dynamic RAM is maintained and is read/write by the processor.

• S1 state is a low wake-up latency sleeping state. In this state, no system context is lost (CPU or chip set) and

hardware maintains all system contexts.

• S3 is called “suspend to RAM” state or stand-by mode. In this state the dynamic RAM is maintained. Dell systems

will be able to go to S3 if the OS and the peripherals used in the system supports S3 state. Linux and Windows
support S3 state.

• S4 is called “suspend to disk” state or “hibernate” mode. There is no power. In this state, the dynamic RAM is not

maintained. If the system has been commanded to enter S4, the OS will write the system context to a non-
volatile storage file and leave appropriate context markers. When the system is coming back to the working state,
a restore file from the non-volatile storage can occur. The restore file has to be valid. Dell systems will be able to
go to S4 if the OS and the peripherals support S4 state. Windows support S4 state.

• S5 is the “soft” off state. There is no power. The OS does not save any context to wake up the system. No data will

remain in any component on the system board, i.e. cache or memory. The system will require a complete boot when
awakened. Since S5 is the shut off state, coming out of S5 requires power on which clears all registers.

The following table shows all the states supported by Dell PowerEdge T20:

Table 2. Supported ACPI Power States

Model Number

Dell PowerEdge T20

NOTE: For any information that you may need, direct your questions to your Dell Marketing contact.

Trademarks used in this text: Dell™ and the DELL logo are trademarks of Dell Inc. Intel®, Pentium®, Xeon®, Core™ and Celeron® are registered
trademarks of Intel Corporation in the U.S. and other countries. Microsoft®, Windows® are either trademarks or registered trademarks of Microsoft
Corporation in the United States and/or other countries.