Benchmarking functions vs procs

benchmark.rb

require 'benchmark'

def f_func(x); 2*x; end
def f_proc_func; proc {|x| 2*x}; end
f_proc_var = proc {|x| 2*x }

n = 1000000

Benchmark.bm(7) do |x|
  x.report("using function:            ") { n.times { |i| f_func(i) } }
  x.report("using function via method: ") { n.times(&method(:f_func)) }
  x.report("using proc func:           ") { n.times(&f_proc_func) }
  x.report("using proc var:            ") { n.times(&f_proc_var) }
end

#                              user       system     total        real
# using function:              0.140000   0.010000   0.150000 (  0.141750)
# using function via method:   0.170000   0.000000   0.170000 (  0.181539)
# using proc func:             0.080000   0.000000   0.080000 (  0.078792)
# using proc var:              0.070000   0.000000   0.070000 (  0.083151)