CPU pipeline and superscalar CPU architectures are used for increasing the performance of a CPU.
CPU Pipeline: A CPU pipeline is used for execution of more than one instruction simultaneously. In a pipeline process each output of an item in a pipeline is fed to the next item as input. Below given is a three stage CPU pipeline where three stages are used for processing an instruction:
Superscalar CPU: In a superscalar CPU architecture multiple execution units are used for executing instructions in parallel. Each execution unit is dedicated for handling separate task like arithmetic operations, logical operations, etc. All the instructions that have to be executed are fetched at the same time. Then they are decoded and sent to a buffer. When an execution unit becomes free the instruction is sent from the buffer to that particular execution unit and is executed.