It used to be that parallel tests bundled up the tasks in "groups" and went one group at a time.
e.g. 12 tests on 4 cores ==> 4 groups with 3 tests each.<p>The problem was that some of the groups might have ended up with tests that take 5 minutes each (finished after 15 minutes) and other groups end up with the 20 second ones (finished after 1 minute). Did that balancing every change?<p>Another question: How does this work for different RSpec formatters? (specifically: junit xml output or html output). Will it still result in a single file?