Update: you might like Time.benchmark

Usage

benchmark "deleting users" do
  User.all.each(&:destroy)
end

Output

deleting users...
took 123.3435 seconds

Script

def benchmark(what, &block)
  require 'benchmark'
  puts "#{what}..."
  result = nil
  time = Benchmark.realtime do
    result = yield
  end
  puts "took #{time} seconds"
  result
end

Have fun 🙂