Superscalar processor

A superscalar processor is a CPU that implements a form of parallelism called instruction-level parallelism within a single processor. It therefore allows faster CPU throughput (the number of instructions that can be executed in a unit of time) than would otherwise be possible at a given clock rate. A superscalar processor executes more than one instruction during a clock cycle by simultaneously dispatching multiple instructions to different execution units on the processor. Each execution unit is not a separate processing unit (called "core") as in multi-core processors, but an execution resource within a single CPU such as an arithmetic logic unit, a bit shifter, or a multiplier.

In Flynn's taxonomy, a single-core superscalar processor is classified as an SISD processor (Single Instruction stream, Single Data stream), though many superscalar processors support short vector operations and so could be classified as SIMD (Single Instruction stream, Multiple Data streams). A multi-core superscalar processor is classified as an MIMD processor (Multiple Instruction streams, Multiple Data streams).