Ray tracing systems and computer-implemented methods perform intersection testing on a bundle of rays with respect to a box. A bundle of rays to be tested for intersection with a box is received, and a first bundle intersection test is performed to determine whether or not all of the rays of the bundle intersect the box, wherein if the first bundle intersection test determines that all of the rays of the bundle intersect the box, an intersection testing result for the bundle with respect to the box is that all of the rays of the bundle intersect the box. If the first bundle intersection test does not determine that all of the rays of the bundle intersect the box, a second bundle intersection test is performed, which determines whether or not all of the rays of the bundle miss the box, the result of which is used to determine the intersection testing result for the bundle with respect to the box.