Low FOV when using Terrain drops FPS

I am encountering something that I cannot easily solve myself, I think it might indicate a bug in the Unity Renderer's Culling logic.

I have a Terrain piece (fairly big) and a camera viewpoint that can rotate via the mouse and adjust FOV using the scroll-wheel.

I have noticed that when I go into the lower FOV values the FPS drop. At first I thought it was an issue because I zoomed into the Terrain but it happens when I look far away up in the air, located kilometers away from the Terrain piece too.

Attaching the Profiler, from FOV at 75, then a big jump in time used as I switch down to FOV 1 -- but always looking away from the Terrain itself.


Notice the time spent by Camera.Render -> Culling -> Terrain.Heightmap.RenderStep3

 

Does anyone else see this? Will file a bug if it cannot be explained away.

 

I noticed it too. Did you find a solution?

 

I ended up filing a bug-report -- I can perhaps find the email-thread with support, but from what I remember they where able to confirm it. I don't know if a fix was ever submitted for the engine.