Specifications

20 PowerEdge M420 Technical Guide
maximum speed supported by the processor, the speed settings in the BIOS and the operating
voltage of the system.
Table 8 lists the memory configuration and performance details for the M420, based on the
population of the number and type of DIMMs per memory channel.
Table 8. Memory speed capabilities
DIMM
type
DIMM 0
# of
DIMMs
Speed (MT/s)
800*
1066*
1333
1600
UDIMM
DR
1
∞
∞
∞
∞
RDIMM
SR
1
∞
∞
∞
∞
DR
1
∞
∞
∞
∞
QR
1
∞
∞
∞
*Although the M420 supports DIMM speeds of 800MT/s and 1066MT/s, you can only purchase
this system with DIMM speeds of 1333MT/s and 1600MT/s on Dell.com/PowerEdge.
Memory RAS features
RAS features help keep the system online and operational without significant impact to performance,
and can decrease data loss and crashing due to errors. RAS aids in rapid, accurate diagnosis of faults
which require service. Table 9 describes the memory RAS features supported on the M420.
Table 9. Memory RAS features
Feature
Description
Dense configuration
optimized profile
Increased memory reliability can be a result from this selectable platform profile
that adjusts parameters to reduce faults regarding refresh rates, speed,
temperature and voltage.
Memory demand and
patrol scrubbing
Demand scrubbing is the ability to write corrected data back to the memory once
a correctable error is detected on a read transaction. Patrol scrubbing proactively
searches the system memory, repairing correctable errors.
Recovery from single
DRAM device failure
(SDDC)
Recovery from Single DRAM Device Failure (SDDC) provides error checking and
correction that protects against any single memory chip failure as well as multi-bit
errors from any portion of a single memory chip.
Failed DIMM isolation
This feature provides the ability to identify a specific failing DIMM channel pair,
thereby enabling the user to replace only the failed DIMM pair.
Memory mirroring:
intra-socket
Memory mirroring is a method of keeping a duplicate (secondary or mirrored)
copy of the contents of memory as a redundant backup for use if the primary
memory fails. The mirrored copy of the memory is stored in memory of the same
processor socket.
Memory address parity
protection
This feature provides the ability to detect transient errors on the address lines of
the DDR channel.
Memory sparing (rank)
Memory sparing allocates one rank per channel as a spare. If excessive correctable
errors occur in a rank or channel, they are moved to the spare area while the
operating system is running to prevent the errors from causing an uncorrectable
failure.