bench-erb.rb

require 'benchmark'
require 'erb'

require 'rubygems'
require 'erubis'

# generate templates
LINES = 1_000

perline = ""
single  = ""

single += "<%\n"
LINES.times do |i|

  perline += "<% #{i} %>\n"
  single  += "#{i}\n"

end

single += "%>"

N = 1_000

Benchmark.bm(17) do |x|


  x.report("erb per-line") do 
    N.times { ERB.new(perline).result }
  end
  GC.start

  x.report("erb single") do
    N.times { ERB.new(single).result }
  end
  GC.start


  x.report("erubis per-line") do 
    N.times { Erubis::Eruby.new(perline).result }
  end
  GC.start


  x.report("erubis single") do
    N.times { Erubis::Eruby.new(single).result }
  end
  GC.start


  x.report("just eval") do
    N.times do 
      LINES.times { |i| i }
    end
  end
  GC.start

end

__END__

The results on my system:

                       user     system      total        real
erb per-line      23.340000   0.060000  23.400000 ( 23.749460)
erb single         1.440000   0.000000   1.440000 (  1.463565)
erubis per-line   10.450000   0.060000  10.510000 ( 10.653146)
erubis single      1.440000   0.010000   1.450000 (  1.461613)
just eval          0.160000   0.000000   0.160000 (  0.162416)