require 'benchmark' n = 10 Benchmark.benchmark do |bm| 3.times do bm.report do n.times do `bin/rspec benchmarks/example_spec.rb` end end end end # Before autoloading matcher class files # 0.000000 0.010000 8.800000 ( 8.906383) # 0.010000 0.010000 8.880000 ( 8.980907) # 0.000000 0.010000 8.820000 ( 8.918083) # # After autoloading matcher class files # 0.000000 0.010000 8.610000 ( 8.701434) # 0.010000 0.010000 8.620000 ( 8.741811) # 0.000000 0.000000 8.580000 ( 8.677235) # # Roughly 2.5% improvement in load time (every bit counts!)