Overview
OoOE allows a processor to avoid being stalled by slow operations (like a cache miss). Instead of waiting for a specific instruction to finish, the CPU looks ahead in the instruction stream and executes any subsequent instructions that are ready.
Key Components
- Instruction Window: A buffer that holds instructions waiting to be executed.
- Reservation Stations: Where instructions wait for their operands.
- Reorder Buffer (ROB): Ensures that instructions are 'retired' (committed to architectural state) in the original program order to maintain correctness.
Benefit
Significantly improves performance by maximizing the utilization of execution units and hiding memory latency.