As faster and higher-performing CPU modules become available, they can be added to or replace existing installed CPU modules to further improve performance.

The system uses symmetric multiple-processing (SMP), so each CPU can access any part of system memory regardless of its mounting location. Adding more CPUs does not affect memory access to any of the installed CPUs.

■High-speed crossbar-type system bus

The high-speed crossbar-type system bus provides high-speed wide-band data transfer.

■ECC memory

ECC functionality protects data on all system buses and in memory, so that any errors in data are automatically corrected. In addition to ECC memory, Chipkill memory protection is supported.

■PCIe is mounted as I/O buses

PCIe, with a maximum bus width of eight lanes is used for the inter-connect bus with the I/O device.

■An optional External I/O Expansion Unit enables I/O slot expansion in the system

Connect an External I/O Expansion Unit to add more PCIe and PCI-X slots to the server.

An External I/O Expansion Unit is connected by a cable to a link card plugged into a PCIe slot in an I/O unit.

■The main components, power supply units, and FAN units can be configured to be redundant

Redundant configurations can be used for the main components, such as a power supply unit, FAN unit, hard disk unit, and PCI card. Implementation of redundant configurations enables operation to continue without interruption even if one of the units making up part of the system fails.

■The main components, power supply units, and FAN units support active replacement/addition

Component replacement and addition during system operation supported for the main components, such as a power supply unit, FAN unit, hard disk unit, System Control Facility (board), system board, and PCI card, with some exceptions.

Dynamic reconfiguration (DR) is used for active replacement and addition of CMU and IOU configuring the system board.

PCI hot-plug (PHP) function enables replacement and addition of PCI Cards while the system is running.

■Automatic reboot on failure

Chapter 1 System Overview 1-5