User Manual

Dell
PowerEdge R710 Technical Guide 34
The DDR3L standard is completely backwards-compatible at standard voltage. DDR3L DIMMs can operate at
1.5V without any limitations beyond standard voltage DDR3 DIMMs. As part of the addition of LV DIMMs, the
platform has certain default behaviors. Whenever possible, if there is no performance degradation, the
platform will default to 1.35V operation when using DDR3L DIMMs. In certain cases, where a configuration is
populated that cannot support 1.35V or a performance degradation would result, the platform defaults to 1.5V
operation. There are also options to override default voltage within allowed limits.
Mirroring
The R710 system supports memory mirroring if identical memory modules are installed in the two channels
closest to the processor (memory not installed in the farthest channel). Mirroring must be enabled in the
System Setup program. In a mirrored configuration, the total available system memory is one-half of the total
installed physical memory.
Sparing
Systems with the Intel Xeon processor 5600 series support memory sparing. Sparing requires identical memory
installed in all three channels. One of the three channels is considered the Spare Channel, and two-thirds of
the total installed memory is usable and is the amount reported during POST and in BIOS setup.
Memory Scrubbing
The PowerEdge R710 memory interface supports memory demand and patrol scrubbing, single-bit correction
and multi-bit error detection. Correction of a x4 or x8 device failure is also possible with SDDC in the Advanced
ECC mode. Additionally, correction of a x4 device failure is possible in the Memory Optimized mode.
Advanced ECC (Lockstep) Mode
In Advanced ECC (Lockstep) mode, the two channels closest to the processor are combined to form one 128-bit
channel. This mode supports Single Device Data Correction (SDDC) for both x4- and x8-based memory modules.
Memory modules must be identical in size, speed and technology in corresponding slots.
Optimizer (Independent Channel) Mode
In Optimizer (Independent Channel) mode, all three channels are populated with identical memory modules.
This mode permits a larger total memory capacity but does not support SDDC with x8-based memory modules.
A minimal single-channel configuration of 1 GB memory modules per processor is also supported in this mode.
Supported Configurations
See the System Memory section in the Installing System Components chapter in the Dell PowerEdge R710
Systems Hardware Owner's Manual on Support.dell.com
.