User Guide
Page 30
... usable memory is not required to prevent data loss in the opposite channel. If a DIMM fails, the data is available from the mirrored DIMM in case a DIMM fails. DIMMs must match (size, technology, manufacturer). The remaining DIMMs are actively in the memory subsystem. DIMM D1 Socket DIMM C1 Socket DIMM B1... DIMM Configuration Example In non-mirrored mode, all data in use at the same time. In determining your memory requirements, the need for mirroring. 12 Intel® Server Board S5000PAL User's Guide
... usable memory is not required to prevent data loss in the opposite channel. If a DIMM fails, the data is available from the mirrored DIMM in case a DIMM fails. DIMMs must match (size, technology, manufacturer). The remaining DIMMs are actively in the memory subsystem. DIMM D1 Socket DIMM C1 Socket DIMM B1... DIMM Configuration Example In non-mirrored mode, all data in use at the same time. In determining your memory requirements, the need for mirroring. 12 Intel® Server Board S5000PAL User's Guide