Memory Ras Features - Dell PowerEdge M420 Technical Manual

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.
DIMM
type
UDIMM
RDIMM
*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.
Reliability, availability, and serviceability (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.
Feature
Dense configuration
optimized profile
Memory demand and
patrol scrubbing
Recovery from single
DRAM device failure
(SDDC)
Failed DIMM isolation
Memory mirroring:
intra-socket
Memory address parity
protection
Memory sparing (rank)
Memory thermal
throttling
For information on memory mirroring and sparing configurations, see the
Systems Owner's Manual
PowerEdge M420 Technical Guide
20
# of
DIMM 0
DIMMs
DR 1
SR 1
DR 1
QR 1
Description
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.
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) 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.
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 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.
This feature provides the ability to detect transient errors on the address lines of
the DDR channel.
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.
This feature helps to optimize power/performance and can also be used to
prevent DIMMs from overheating.
on Support.Dell.com/Manuals. Memory RAID is not supported.
Speed (MT/s)
800* 1066* 1333
∞ ∞
∞ ∞
∞ ∞
∞ ∞
1600
∞ ∞
∞ ∞
∞ ∞
∞
Dell PowerEdge M420