1. Installing Internal Optional Devices
Express5800/R120h-1M User’s Guide
77
Chapter 2 Preparations
Memory Function
The device has, as Memory RAS function, "Advanced ECC Function (x4 SDDC)", "Memory Mirroring Function"
and "Memory Sparing Function", "Fault tolerant memory function (ADDDC)"
Single Device Data Correction (SDDC) is afunction to restore the data automatically in case one of memory chips
stored on DIMM breaks.
The mother board of this device has six systems of "Memory Channel", which controls memory.
"Memory Mirroring Function" and "Memory Sparing Function" are functions to retain redundancy by monitoring
of memories and switching among channels.
Memory Controller 1
Memory Controller 2
Memory Controller 1
Memory Controller 2
