viz.collision enabled lag

[Gekitatsu]

Setup

-City enviorment (Buildings/tress/cars/etc)(As 1.ive file)
-Mainview placed at a location in the city.

Goal

Move the camera around the city without being able to move through any objects in the city.

Problem

When I add viz.collision(viz.On) to enable collision for MainView my framerate drops to 22 from 60. Anybody have any idea how to bring my framerate back up to 60 with a collision enabled mainview?


-Note The mainview is not linked to any objects.