User`s guide

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2: System Overview and Options
Functional Architecture
The Silicon Graphics Prism is based on the SGI NUMAflex architecture, which is a
shared-memory system architecture that is the basis of SGI HPC servers and
supercomputers. The NUMAflex architecture is specifically engineered to provide
technical professionals with superior performance and scalability in a design that is easy
to deploy, program, and manage. It has the following features:
Shared access of processors, memory, and I/O. The Super Hub (SHub) ASICs and the
NUMAlink interconnect functions of the NUMAflex architecture enable applications to
share processors, memory, and I/O devices.
• Each Super-Hub (SHUB) ASIC in the system acts as a memory controller between
processors and memory for both local and remote memory references.
• The NUMAlink interconnect channels information between all the modules in the
system to create a single contiguous memory in the system of up to 192 GB and
enables every processor in a system direct access to every I/O slot in the system.
Together, the SHub ASICs and the NUMAlink interconnect enable efficient access to
processors, local and remote memory, and I/O devices without the bottlenecks
associated with switches, backplanes, and other commodity interconnect technologies.
System scalability. The NUMAflex architecture incorporates a low-latency,
high-bandwidth interconnect that is designed to maintain performance as you scale
system computing, I/O, and storage functions. For example, the computing dimension
in some system configurations can range from 4 to 16 processors in a single system image
(SSI).
Efficient resource management. The NUMAflex architecture is designed to run complex
models and, because the entire memory space is shared, large models can fit into
memory with no programming restrictions. Rather than waiting for all of the processors
to complete their assigned tasks, the system dynamically reallocates memory, resulting
in faster time to solution.