From: Roger Pack Date: 2009-07-09T13:04:06+09:00 Subject: [ruby-core:24227] Re: Performance issue with Prime class under Ruby 1.8.6 in Windows > I'm willing to submit a patch, but I am unclear what the next steps are. Yeah you'd have to figure out exactly *why* it is so slow within the ruby core, then figure out a patch to overcome that slowness, then file a report to redmine.ruby-lang.org If I were you I might consider just switching to 1.9 :) Also http://rubyforge.org/tracker/index.php?func=detail&aid=19034&group_id=426&atid=1700 might be of interest. Also running your code against ruby-prof might help you see what's going on. GL. =r