Measure Gem loading time in your Rails APP

measure_gem_loading_time.rb

# Disclaimer: this solution has been taken from the post: http://stackoverflow.com/a/5071198/784270

# navigate to the bundler gem and in lib/bundler/runtime.rb, 
# find the line that does Kernel.require and wrap it like this

puts Benchmark.measure("require #{file}") {
  Kernel.require file
}.format("%n: %t %r")

# Add 

require 'benchmark'

# to config/boot.rb

# Start the console / server to see the benchmark.
# If you want to measure the total loading time of your Rails app, you can use the solution
# proposed in: http://erik.debill.org/2011/02/19/ruby-start-up-times

echo puts Time.now > test_script
time rails runner test_script