Vector Processor

A vector processor, or array processor, is a central processing unit (CPU) that implements an instruction set containing instructions that operate on one-dimensional arrays of data called vectors. This is in contrast to a scalar processor, whose instructions operate on single data items. Vector processors can greatly improve performance on certain workloads, notably numerical simulation and similar tasks. Vector machines appeared in the early 1970s and dominated supercomputer design through the 1970s into the 90s, notably the various Cray platforms. The rapid rise in the price-to-performance ratio of conventional microprocessor designs led to the vector supercomputer's demise in the later 1990s.

Today, most commodity CPUs implement architectures that feature instructions for a form vector processing on multiple (vectorized) data sets, typically known as SIMD (Single Instruction, Multiple Data). Common examples include VIS, MMX, SSE, AltiVec and AVE. Vector processing techniques are also found in video game console hardware and graphics accelerators. In 2000, IBM, Toshiba and Sony collaborated to create the Cell processor, consisting of one scalar processor and eight vector processors, which found use in the Sony PlayStation 3 among other applications.

Other CPU designs may include some multiple instructions for vector processing on multiple (vectorised) data sets, typically known as MIMD (Multiple Instruction, Multiple Data) and realized with VLIW. Such designs are usually dedicated to a particular application and not commonly marketed for general purpose computing. In the Fujitsu FR-V VLIW/vector processor both technologies are combined.