Out-of-order execution

First introduced with IBM's POWER1 microprocessor in 1990, out-of-order execution, also called dynamic execution, is a processing technique used in most modern CPUs. Rather than only executing instructions in the order they appear in a program, the processor sometimes executes instructions "out of order," depending on the availability of data. Doing so minimizes wasted clock cycles, because processing can begin on pending instructions even if other instructions are experiencing a delay.

Clock cycle, CPU terms, IBM, Instructions, P6