It means using Ruby 1.9.3 patch level 194 took 3.7 seconds.

ok, but on which code? he only posted the python implentation

which btw is a straight port of the original ruby script, that takes 53 minutes to run

so: 3.7seconds seems quite impossible

I'm using the ruby code from the blog post. I'm also just running the 15 first test cases out of the 10001 he uses.