6.4) Parallel Computers

Parallel computers contain multiple CPUs, provide more memory, improved performance and are utilised for parallel computing. The machines that make up a cluster like ARC2 are an example of these. An easy and useful way of classifying parallel computers is via their memory model, or how the CPUs view the available memory. They can be divided into:

Shared Memory Machines – CPUs share a single memory address space. All the processors have access to a pool of shared memory. An example of these are the individual servers that make up ARC2.

Distributed Memory Machines - each processor has separate local memory. Must do message passing to exchange data between processors. An example of this type is ARC2, as need to use message passing if using more than one node.