The HP Integrity Superdome architecture is modular, with components that can be used to construct several different server-class computer products based on Intel Itanium 2 and future PA-RISC processors. The same cell board can support Intel Itanium 2 processors (1.5 GHz with 6 MB L3 cache), mx2 Dual-Processor Modules (two Intel Itanium 2 processors sharing a large, 32 MB L4 cache), PA-8800 processors, future Intel Itanium processors, or future PA-RISC processors (PA-8900). PA-RISC and Intel Itanium 2 processors cannot be mixed in the same system. Intel Itanium 2 processors and mx2 Dual-Processor Modules are supported in the same system, but only in different hard partitions. Such modularity helps provide investment protection—you can simply add or change cell boards as system requirements change.
With the new mx2 Dual-Processor Module, the HP Integrity Superdome platform supports a variety of system configurations, from 2 to 128 processors. (There are three models to choose from—the largest is a 64-processor or 64–mx2 Dual-Processor Module system [4 to 128 processors] with a scalable memory and I/O system.) The system is extremely flexible and has a cell-based hierarchical crossbar architecture that can be configured as one large symmetric multiprocessor or as several independent nPartitions. In an Integrity Superdome system, any processor on any nPartition can directly address any byte of memory on any nPartition, through processor-issued load or store instructions.
There are three basic components in the Integrity Superdome architecture: the cell or cell board, the crossbar backplane, and the PCI-X-based I/O subsystem (the PCI-based I/O subsystem is supported when an existing HP 9000 Superdome is upgraded to an Integrity Superdome). Figure 3 is an illustration of this architecture.
Figure 3. The HP Integrity Superdome’s hierarchical crossbar architecture