gistfile1.txt

% for i in {1..5}; do JAVA_HOME=/home/nahi/java/jdk1.6.0_31 jruby --server -X+C bench/bench.rb resource/010000.csv; done                  
150.0
141.0
141.0
169.0
179.0
% for i in {1..5}; do JAVA_HOME=/home/nahi/java/jdk1.7.0_03 jruby --server -X+C bench/bench.rb resource/010000.csv; done
115.0
103.0
122.0
106.0
105.0
% for i in {1..5}; do JAVA_HOME=/home/nahi/java/jdk1.7.0_u4_b17 jruby --server -X+C bench/bench.rb resource/010000.csv; done
178.0
156.0
125.0
119.0
187.0
% for i in {1..5}; do ruby bench/bench.rb resource/010000.csv; done    
278.007422
286.62199100000004
293.31006199999996
294.658127
291.171229
% ruby -v
ruby 2.0.0dev (2012-03-23 trunk 35121) [x86_64-linux]
% jruby -v
jruby 1.7.0.dev (ruby-1.9.3-p139) (2012-03-27 c725e7d) (Java HotSpot(TM) 64-Bit Server VM 1.7.0_03) [linux-amd64-java]
% 

Of course I expect u4_b17 is the fastest.