Multiprocessing divides the
processing loads across several
CPUs. Two processors are not twice as fast as one because the main CPU controls the
scheduling and
resource assignments.
Windows NT with two processors is
theoretically 150% faster than one processor, but I've seen an average of 167% increase on my
home server.
There are two types of multiprocessing:
Symmetric Processing
Symmetric shares the total processing load among all available processors as equally as possible.
Asymmetric Multiprocessing
Asymmetric dedicates certain program threads to particular processors.