xSeries SMP Expansion Module is an upgrade module that provides four additional CPU connectors, 32 MB of L4 system cache, 16 memory connectors to support additional 16 GB of system memory, and three SMP expansion ports.This module is installed on the xSeries 440 centerplane next to the standard module and is compatible with all models of xSeries 440. Prior to installation, the standard SMP expansion module must be fully populated with four Xeon MP processors of the same type and speed.