Sparing; Mirroring; Memory Scrubbing - Dell PowerEdge M915 Technical Manual

Dell

Quad-rank DIMM types can support speeds up to 1333MT/s.

If DIMMs of different speeds are mixed, all channels will operate at the fastest common
frequency.

7.6 Sparing

Memory sparing (spare bank) is supported in certain configurations with 32 memory modules installed.
If online sparing is enabled, identical DIMMs must be installed in the same slots across each channel.
The memory sparing feature must be enabled in the Memory Information screen in the System Setup
programs. To use memory sparing, node interleaving must be disabled.
For more information on memory sparing, see the Dell PowerEdge Modular Systems Hardware
Owner's Manual on Support.Dell.com.

7.7 Mirroring

Memory mirroring is not supported.

7.8 Memory Scrubbing

The M915 memory interface supports memory scrubbing (sequential or redirection) and patrol
scrubbing, single-bit correction, and multi-bit error detection. The failure of an x4 DRAM device
results in errors to one ECC symbol and can be corrected (chipkill). The failure of an x8 DRAM device
results in errors to two ECC symbols, and can be detected but cannot be corrected.
PowerEdge M915 Technical Guide 28