Laravel : Models relations vs ORM

I am working on a project that uses the ORM heavily instead of model relationships in the controller to get to the data (for eg: using leftJoins instead of establishing proper model relationships using hasMany etc and then retrieving through that)

My question is actually to do with the performance. Is using model relationships to access data faster than using leftJoins? I am not sure if Laravel actually does perform a leftJoin under the hood.

I am on a tight schedule so I want to decide if its actually worth trying to refactor the code to use the model relationships and if it would provide gains in performance?

Thanks in advance

via Chebli Mohamed