Compared to Django, many people told me Rails will load everything that make it resource hungry. Rails has lots of magic.

How to deal with the resource usage so that the performance and resource usage comparable to other lightweight Ruby framework? And is it good idea to hack everything to achieve this?

In PHP, I use Drupal because it has many modules and I hack nearly everything in core and modules to reduce the resource usage. In Python, Pylons is easier than Django, but I dont have much time to code myself. Rails has more tools, but the resource usage is the question.