(
Symmetric
Multi
Processing) An architecture in which two or more processing units share the same memory. SMP dates back to the 1960s when IBM offered a System/360 dual-CPU model. Digital Equipment followed, and companies such as Sequent, Pyramid and Encore specialized in SMP on Unix platforms. Early SMP systems contained multiple single-core CPUs, which evolved into today's chips with multiple cores that are used in every computing device from servers to smartphones (see
multicore). All major operating systems support SMP. See
Sequent,
Encore and
Fujitsu Siemens.
A Pool of Resources
One CPU with multiple cores is common in today's computers, and one of the cores loads the SMP operating system. There is only one instance of the OS, and it uses all the cores as a pool of processing resources that execute simultaneously. If one core fails, the system typically goes down. In some cases, the defective core can be disengaged in the BIOS. Contrast with
MPP. See
multicore and
NUMA.
SMP and MPP Processing
With symmetric multiprocessing (SMP), the processing cores (or CPUs) are assigned the next available task or thread that can run concurrently. In massively parallel processing (MPP), the problem is broken up into separate pieces that are processed simultaneously.