Base system can be configured with 1 to 4 processors, both single-core and dual-core. (NOTE: Only like processors can be configured together in the same system.) Base system does not include processor modules, a memory carrier board, memory, hard disk drives or a DVD drive. One power supply is included. May select a second power supply for redundancy. Standard core I/O includes one dual-port GigE LAN card and one dual-channel Ultra320 SCSI controller card.