How fast can a computer count or iterate?

CPUs are fast. Today we talk about 4-5 GHz. Counting from zero to 4.3 billion on all cores simultaneously for 10 seconds as fast as possible.

Real-world Performance Examples

My 4 core laptop (11th Gen Intel(R) Core(TM) i7-1165G7 @ 2.80GHz) can do about 16 billion/second

My 12 core Asus NUC (13th Gen Intel(R) Core(TM) i5-1340P) can do about 24 billion/second

Overview

This program tests CPU performance by running intensive counting operations across multiple threads. It can run in two modes:

• Regular benchmark: Counts from UINT_MAX down to 0 on each thread and measures total time
• Timed benchmark: Counts continuously for a set period (10 seconds) and measures operations completed

Compilation and Running

make
bin/count          # Regular benchmark mode
bin/count --timed  # Timed benchmark mode (10 seconds)

Understanding the Results

• Complete loops: Each loop counts from UINT_MAX (4,294,967,295) down to 0
• Iterations: Individual counting operations performed
• Speedup from logical cores: Measures the performance benefit from using hyperthreading/SMT

The benchmark primarily tests integer operations and is affected by:

• CPU clock speed
• CPU architecture
• Number of cores
• Memory performance

Try it on different systems and compare your results!