NEC N8100- 1241F User Manual page 275

Depending on specification of memory controller, the spare memory is set in unit of rank memory.
The logical memory capacity of single rank memory differs from that of dual rank memory when
online spare memory is specified.
Single rank memory configuration
Logical memory capacity = (Physical memory capacity * Number of DIMMs) – (Physical
memory capacity)
Dual rank memory configuration
Logical memory capacity = (Physical memory capacity * Number of DIMMs) – (Physical
memory capacity / 2)
The server supports the following product number.
N8102-254/277 (1GB memory): Single rank
N8102-255/256/257/278/279/280 (2GB/4GB/8GB memory): Dual rank
Upgrading Your Server 9-35