gistfile1.rb

require 'benchmark'
require 'psych'
require 'yaml'

data = [ 1 , { "hello hello" => "moo moo", :aaa => [] } ] * 100

yaml = YAML.dump(data)
time = Benchmark.realtime { 10000.times { YAML.load(yaml) }}

puts "Time #{YAML}: #{time}"

YAML::ENGINE.yamler = "syck"
time = Benchmark.realtime { 10000.times { YAML.load(yaml) }}

puts "Time #{YAML}: #{time}"

__END__
~/tmp$ ruby -v test.rb 
ruby 1.9.3p0 (2011-10-30 revision 33570) [x86_64-darwin11.2.0]
malloc_limit=100000000 (8000000)
heap_min_slots=500000 (10000)
Time Psych: 15.395857
Time Syck: 3.098056