Symmetric multiprocessingSymmetric multiprocessing (SMP) is a multiprocessor computing architecture where all processorss can access, and are equally close to, all random access memory locations.
SMP is the most common small computer multiprocessor architecture. However, SMP does not scale well beyond roughly 16 processors, due to the difficulties of designing hardware that will share the memory pool between processors without becoming a system bottleneck. (See Amdahl's law).
The logical progression from SMP systems is the NUMA architecture, where the requirement that all processors be equally close to all memory locations is relaxed.