FastXMLWriter vs XMLWriter

gistfile1.rb

require 'benchmark'
require 'benchmark/ips'

require 'marc'
require 'marc/fastxmlwriter'

record = MARC::Reader.new('test/one.dat').first

puts RUBY_DESCRIPTION

Benchmark.ips do |x|
  x.report('MARC::XMLWriter    ') do
    str = MARC::XMLWriter.encode(record).to_s
  end
  
  x.report("MARC::FastXMLWriter") do
    str = MARC::FastXMLWriter.encode(record)
  end
  
  x.compare!
end

# ruby 2.2.0p0 (2014-12-25 revision 49005) [x86_64-darwin13]
#
# Calculating -------------------------------------
#  MARC::XMLWriter        32.000  i/100ms
#  MARC::FastXMLWriter   570.000  i/100ms
# -------------------------------------------------
#  MARC::XMLWriter        326.851  (± 2.1%) i/s -      1.664k
#  MARC::FastXMLWriter      5.882k (± 2.0%) i/s -     29.640k
#
# Comparison:
#  MARC::FastXMLWriter:     5881.9 i/s
#  MARC::XMLWriter    :      326.9 i/s - 18.00x slower
#
#  =========
#
# jruby 1.7.18 (1.9.3p551) 2014-12-22 625381c on Java HotSpot(TM) 64-Bit Server VM 1.8.0-b132 +jit [darwin-x86_64]
#
# Calculating -------------------------------------
#  MARC::XMLWriter        12.000  i/100ms
#  MARC::FastXMLWriter   461.000  i/100ms
# -------------------------------------------------
#  MARC::XMLWriter        429.220  (±15.6%) i/s -      2.076k
#  MARC::FastXMLWriter      8.639k (± 6.2%) i/s -     43.334k
#
# Comparison:
#  MARC::FastXMLWriter:     8638.9 i/s
#  MARC::XMLWriter    :      429.2 i/s - 20.13x slower
#