symbol_to_proc_benchmark.rb

require 'rubygems' and require 'activesupport' if RUBY_VERSION == "1.8.6"

p RUBY_VERSION
p RUBY_RELEASE_DATE

require "benchmark"
SIZE = 1_000
TIMES = 10_000
RANGE = (1..SIZE)

print "      "
Benchmark.bm do |bm|
  bm.report " block" do
    TIMES.times do
      RANGE.map { |n| n.to_s }
    end
  end
  bm.report "symbol" do
    TIMES.times do
      RANGE.map &:to_s
    end
  end
end

The 1.8.6 results

"1.8.6"
"2008-03-03"
            user     system      total        real
 block 35.650000   0.050000  35.700000 ( 35.717756)
symbol106.290000   3.940000 110.230000 (111.735975)

"1.8.6"
"2008-03-03"
            user     system      total        real
 block 35.230000   0.020000  35.250000 ( 35.282963)
symbol 99.980000   0.120000 100.100000 (100.431351)

The 1.9.0 results

"1.9.0"
"2007-12-25"
            user     system      total        real
 block 13.210000   0.000000  13.210000 ( 13.221047)
symbol 11.060000   0.020000  11.080000 ( 11.099965)

"1.9.0"
"2007-12-25"
            user     system      total        real
 block 12.640000   0.010000  12.650000 ( 12.671435)
symbol 11.100000   0.000000  11.100000 ( 11.101745)