Does Raycasting require a PhysX enabled video card?

After having some problems implementing raycasting into my project, I decided to try running my project on another machine.

To my surprise, while raycasting would never produce a hit on a collider on machine #1, machine #2 would behave as expected.

I've confirmed that both have:

• The same version of Unity

• An exact copy of the project files

• The same version of Windows

The only difference I've been able to find is that machine #1 does not have onboard PhysX and #2 does.

Does Unity require your video adapter to have on-board physics acceleration to use raycasting?

No other physics features seem to be affected, and I would have assumed that Unity had a non-hardware fallback if it did use accelerated raycasting.