Where did you see that? To be honest, if something is saying 0.0s, then it鈥檚 probably a measurement error 
Some key things we use to improve RSpec performance are:
-
GitHub - grosser/parallel_tests: Ruby: 2 CPUs = 2x Testing Speed for RSpec, Test::Unit and Cucumber
-
test-prof/docs/recipes/let_it_be.md at master 路 test-prof/test-prof 路 GitHub (we wrap this in a
fab!helper in our codebase)