Single Instruction and Multiple Data stream (SIMD)

In this organisation, multiple processing elements are working under the control of a one control unit. It has multiple data stream and only one instruction. All the processing fundamentals of this organization get the same instruction broadcast from the CU. Main memory can also be separted into modules for producing multiple data streams acting as a distributed memory as shown in Figure 5. Thus, all the processing fundamentals simultaneously implement the same instruction and are supposed to be 'lock-stepped' together. Each processor obtain the data from its own memory and hence it has on distinct data streams. (Some systems also supply a shared global memory for communications.) Every processor must be allowed to finish its instruction previous to the next instruction is taken for implememtation. Thus, the implementation of instructions is synchronous. Examples of SIMD organisation are PEPE, ILLIAC-IV, , STARAN, BSP, DAP, MPP, and the Connection Machine (CM-1).

This type of computer organisation is represent as: