Branch Prediction Failures Explained: Pipeline Bubbles, Speculative Execution

Processing a sorted array can be six times faster than an unsorted one due to CPU branch prediction. In a benchmark, an unsorted array caused a 50% branch misprediction rate, drastically reducing instructions per cycle. Modern CPUs predict branch outcomes to avoid stalling their multi-stage instruction pipelines. When a prediction is wrong, it creates a 'pipeline bubble,' wasting 15-20 clock cycles of work.