Cyphesis broadphase collision detection

Currently the collision detection is performed for every two entities in the world. This is very inefficient model. Most games before handling collision between pairs of entities do some sort of space partitioning or entity bbox sorting to exclude unlikely collisions.
This process is called broadphase collision detection and the algorithms that handle it are well developed and highly efficient ( bullet library has good one ).
For games with large amount of entites its a must.