The SGI Origin 3000 series comprises a family of multiprocessor distributed shared memory (DSM) computer systems. The SGI Origin 3000 series uses a global-address-space cache-coherent multiprocessor that scales to 512 processors (~410 GFLOPS peak) in a cache-coherent domain. Four processors, each with 8 Mbytes of private secondary cache, are connected at a Bedrock ASIC. This Bedrock ASIC acts as a crossbar between the processors, local SDRAM memory, the network interface, and the I/O interface. Four Bedrocks, each supporting four processors, are connected to an 8–ported router that can connect up to 32 router chips in a maximum 4 × 4 × 32 extended hypercube topology. The modularity of the DSM approach combines the advantages of low entry-level cost with global scalability in processors, memory, and I/O.
Initial versions of the SGI Origin 3000 series are based upon the MIPS R12000 processor. The MIPS R12000 processor is a four-way, 64-bit superscalar RISC processor. “Four-way” means that it fetches and decodes four instructions per clock cycle and issues them to five fully pipelined execution units. “Superscalar” means that it has enough independent, pipelined execution units that it can complete more than one instruction per clock cycle. The MIPS R12000 also has speculative branching and out-of-order execution and is initially designed with a 400-MHz clock speed.
The SGI Origin 3000 series uses a PCI-based I/O subsystem as its primary I/O protocol. A Crosstalk I/O system, that is compatible with some XIO boards from Origin 2000 and Octane systems, is available to support legacy I/O devices and certain specialized devices such as HIPPI-6400.
Table 2-1 describes ranges of system capacities and performance.
Table 2-1. System Configuration Ranges
Category | Minimum | Maximum |
|---|---|---|
Number of Processors | 2 | 512 |
Peak Performance | ~1600 MFLOPS | ~410 GFLOPS |
C-brick Memory Capacity | 0.512 Gbytes | 8 Gbytes |
System Main Memory Capacity | 0.512 Gbytes | 1024 Gbytes |
Number of I/O Channels | 1 | 128 |
Aggregated peak I/O bandwidth | 0.768 GB/s | ~ 152 GB/s |
Table 2-2 describes the three classes of the SGI Origin 3000 series systems.
Table 2-2. SGI Origin 3000 Series Systems
Series | Description |
|---|---|
SGI Origin 3200 | Contains 2 to 8 processors with a maximum of 2 I/O bricks in a short rack. Additional racks can be added for disks. |
SGI Origin 3400 | Contains 4 to 32 processors. The standard processor and I/O configuration is contained in a single tall rack. However, the configuration can be expanded to include a second tall rack for larger I/O configurations. Additional disk racks can be added as required. |
SGI Origin 3800 | Contains from 16 processors to 512 processors (from one to sixteen tall racks) and a maximum of eight I/O racks. Each I/O rack contains a maximum of eight I/O bricks. Additional disk racks can be added as required. |