Hello, We receive a new PC based on I Core 7 on Windows 7. So i try to compare the use processors resources of each Ruby interpretor (JRuby,IronRuby,Ruby 1.9.1 ). I do the same (stupid) treatment by 1 to 8 threads, and measure the global duration. (test program is on attachment) Here is the result. c:\usr\ruby\local>jruby thread_bench.rb 1.8.7, java, 2010-05-12 1000 iterations by 1 threads , Duration = 2772 ms 500 iterations by 2 threads , Duration = 2076 ms 333 iterations by 3 threads , Duration = 1884 ms 250 iterations by 4 threads , Duration = 1848 ms 200 iterations by 5 threads , Duration = 1814 ms 166 iterations by 6 threads , Duration = 1755 ms 142 iterations by 7 threads , Duration = 1866 ms 125 iterations by 8 threads , Duration = 1538 ms c:\usr\ruby\local>ir thread_bench.rb 1.8.6, i386-mswin32, 2009-03-31 1000 iterations by 1 threads , Duration = 2257 ms 500 iterations by 2 threads , Duration = 1305 ms 333 iterations by 3 threads , Duration = 1055 ms 250 iterations by 4 threads , Duration = 880 ms 200 iterations by 5 threads , Duration = 1026 ms 166 iterations by 6 threads , Duration = 940 ms 142 iterations by 7 threads , Duration = 989 ms 125 iterations by 8 threads , Duration = 1098 ms c:\usr\ruby\local>ruby19 thread_bench.rb 1.9.1, i386-mswin32, 2010-01-10 1000 iterations by 1 threads , Duration = 7318 ms 500 iterations by 2 threads , Duration = 7393 ms 333 iterations by 3 threads , Duration = 7335 ms 250 iterations by 4 threads , Duration = 7367 ms 200 iterations by 5 threads , Duration = 7450 ms 166 iterations by 6 threads , Duration = 7343 ms 142 iterations by 7 threads , Duration = 7349 ms 125 iterations by 8 threads , Duration = 7454 ms So it's seem that IronRuby has better use of cpus than JRuby ? Attachments: http://www.ruby-forum.com/attachment/4825/thread_bench.rb -- Posted via http://www.ruby-forum.com/.