Rack
(Contains 4 IRUs)
Blade | | | | |
| Individual Rack Unit (IRU) |
| (Contains 5 blades) | |
Blade slot 0 | Blade slot 1 | Blade slot 2 | Blade slot 3 | Blade slot 4 |
Figure 3-3Blade, IRU and Rack Components
System Architecture
The Altix 450 computer system is based on a distributed shared memory (DSM) architecture. The system uses a global-address-space, cache-coherent multiprocessor that scales up to 76 Intel 64-bit processor cores in a single rack. Because it is modular, the DSM combines the advantages of lower entry cost with the ability to scale processors, memory, and I/O independently.
The system architecture for the Altix 450 system is a fourth-generation NUMAflex DSM architecture known as NUMAlink 4. In the NUMAlink 4 architecture, all processors and memory are tied together into a single logical system with special crossbar switches (routers). This combination of processors, memory, and crossbar switches constitute the interconnect fabric called NUMAlink. There are two internal router switches on each 5U IRU enclosure.
The basic expansion building block for the NUMAlink interconnect is the processor node; each processor node consists of a Super-Hub (SHub) ASIC and one or two 64-bit processors with three levels of on-chip secondary caches. The Intel 64-bit processors are connected to the SHub ASIC via a single high-speed front side bus.
The SHub ASIC is the heart of the processor and memory node blade technology. This specialized ASIC acts as a crossbar between the processors, local SDRAM memory, and the network
