To achieve optimum performance from an SMP system, you must maintain the correct number of engines.
An engine represents a certain amount of CPU power. It is a configurable resource like memory.
Adaptive Server uses a load-balancing algorithm to evenly
distribute the load among the engines. In process mode, if your
server connections use Component Integration Services (CIS), they
are affinitied to a single engine, and cannot migrate from one engine
to another. This limitation does not apply to threaded mode.