Parallel Programming Guide for HP-UX Systems

Introduction to parallel environments
Individual and clustered workstations/servers
Chapter 1 5
Individual and clustered workstations/servers
Both individual and clustered workstations/servers are suitable for running high
performance, technical computing programs. These workstations or servers can have one or
more CPUs. In general, workstations are not configured with more than two CPUs.
Conversely, servers are often configured for up to 64 CPUs. Clustered systems can include a
few systems (nodes) or as many as 1000+ systems. These nodes can be linked by Ethernet or
by some high-speed interconnect which has low latency and very high bandwidth.
With either individual or clustered systems, the goal is to use the multiple processors in
parallel to execute an application “n” times faster, where “n” represents the number of
processors. Achieving the desired performance can be difficult, especially as the number of
processors grows larger. Performance typically depends on the scalability of a program—and
how scalable a program is depends on many things, including algorithm(s) used, size of the
problem being solved, physical performance characteristics of the system, and how well
optimized the program is for the platform pair it is running.