gistfile1.rb

require 'benchmark'
include Benchmark
n = 10000000
Benchmark.bm do |test|
 
  test.report("Double quotes:") do
    n.times do |x|
      str = "A string without newline"
    end
  end
  
  test.report("Single quotes:") do
    n.times do |x|
      str = 'A string without newline'
    end
  end
  
end

#       user     system      total        real
# Double quotes:  6.120000   2.030000   8.150000 (  8.299323)
# Single quotes:  6.080000   2.170000   8.250000 (  8.286099)