SIngle quote vs. Double quote with no interpolation

Benchmark IPS output

[1] pry(main)> Benchmark.ips do |x|
[1] pry(main)*   x.config(:time => 5, :warmup => 2)
[1] pry(main)*   x.report('single quote') { 'hi there' }
[1] pry(main)*   x.report('doulbe quote') { "hi there" }
[1] pry(main)*   x.compare!
[1] pry(main)* end  
Calculating -------------------------------------
        single quote     72754 i/100ms
        doulbe quote     75296 i/100ms
-------------------------------------------------
        single quote  5228109.3 (±31.8%) i/s -   21680692 in   4.996617s
        doulbe quote  5223542.7 (±31.4%) i/s -   21835840 in   4.996256s

Comparison:
        single quote:  5228109.3 i/s
        doulbe quote:  5223542.7 i/s - 1.00x slower