Branch Prediction

Definitions

1. A CPU optimization that guesses which way a conditional branch (if/else) will go and speculatively executes that path before the condition is evaluated. If the prediction is right (~95% accuracy on modern CPUs), execution continues without delay. If wrong, the speculative work is discarded (pipeline flush penalty of ~15-20 cycles). Sorting data can improve branch prediction accuracy.

   In plain English: The CPU guessing which way an if-statement will go and starting to execute ahead of time, discarding the work if it guessed wrong.

   Example: "Processing a sorted array is faster than unsorted because the branch predictor learns the pattern — the famous Stack Overflow answer about branch prediction."

Related Terms

• Clock Speed
• Overclocking
• Register
• CPU Cache
• SIMD
• NUMA
• NVMe
• L1 Cache
• L2 Cache
• L3 Cache
• Memory Alignment
• Performance Counter
• Superscalar
• FLOPS
• On the Metal