Overview

Symmetrical multiprocessing (SMP) is the ability of two or more processes (or multiple threads of a threaded application) to execute simultaneously on two or more CPUs. This concurrency of execution greatly improves performance. Additionally, it affords customers the opportunity to extend the life and increase the cost-effectiveness of their multiprocessor systems by adding CPU cards (and their compute power) to their multiprocessors rather than buying more systems.

Digital UNIX supports an implementation of SMP that is designed to optimize the performance of compute servers (systems dedicated to compute-bound, multithreaded applications) and data servers (file servers, DBMS servers, TP systems, and mail routers that serve a large number of network clients). In addition, Digital UNIX supports multithreaded application development in an SMP environment. Note that SMP does not adversely affect using a multiprocessor as a timesharing system.