Reference Guide

Description
Reference
Designator
Volatility Description
User
Accessible for
external data
Remedial Action
(action necessary
to lose data)
bytes).One Device
present on each DIMM.
Stores memory
manufacturer data and
timing information for
correct operation of
system memory.
RTC CMOS BATTERY Volatile battery back-
backed CMOS memory
256 bytes. Stores CMOS
information.
No Removing the on
board Coin Cell
battery.
Video memory –
type – see next
column
UMA
architecture-
uses system
memory.
Volatile memory in off
state.
UMA uses main system
memory size allocated
out of main memory.
No Enter S3-S5 state
below.
Hard drive User
replaceable
Non-volatile magnetic
media, various sizes in
GB.
Yes Low level format.
CD-ROM/RW/
DVD/ DVD+RW/
Diskette Drives
User
replaceable
Non-volatile
optical/magnetic media.
Yes Low level
format/erase.
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 (DDR4, 2133 MHz). 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 chipset) 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 Windows7 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 7 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