Multiprocessor systems consist of 2 to 16 central processing units and one or more I/O processor units. The advantages lie in increased availability and a corresponding improvement in performance.
Efficient use of multiprocessor systems requires multiprocessor-capable applications. This means that the application must be able to process the requirements not only in parallel, but also without any significant mutual impairment.
Increased availability
Given appropriate hardware redundancy, whenever one of the hardware components breaks down, the system performs automatic reconfiguration without interrupting the current session.
Improved performance
In multiprocessor mode, i.e. under the control of one BS2000 operating system, a number of tasks can be processed in parallel (depending on the number of CPUs). To ensure that this increased performance capacity can be utilized, there must always be enough tasks available for parallel processing.
It should be remembered that each task can only make use of the capacity of one CPU. This means that improvements in response time behavior are limited, the only possibility being the reduction by the other CPUs of the wait times for CPU allocation. The same applies to batch applications: the runtime of a batch application can only be significantly reduced by parallelizing the pure computing requirement.
Note that the amount of CPU time used for a task is (with the same work) generally somewhat higher than on the corresponding uniprocessor.
For details, see section “Scaling behavior of multiprocessor systems”.