Understaning log file response times

Hi everyone,
I'm trying to understand where my application spends time while being
generated. In the log file I see entries such as:
Completed in 368ms (View: 32, DB: 1) | 200 OK
Since everything is cached, the view and DB time are very small. My
question is can I assume the rest of the time is spent in the
controller? Is there a way to dig deeper into the data (other than
paying new relic a hefty some for their services).