PointLight and FPS

[gismo]

I noticed that my fps drops down quite a lot when using one PointLight. I never thought that it would have such a big impact on the performance.
Is this a normal behavior? Where is the bottleneck (GFX card, driver, OpenGL, Jogl, Xith or maybe the shape geometry)?

My scene contains basically one terrain shape (IndexedTriangeStripArray) and I got a GeForce 3 and P4 2.4Ghz.

Terrain (350k) - w/o light 20 fps
Terrain (350k) - one ambient light 20 fps
Terrain (350k) - one directional light 16 fps
Terrain (350k) - one point light 10 fps
Terrain (350k) - one of each 10 fps

Terrain (110k) - w/o light 31 fps
Terrain (110k) - one ambient light 30 fps
Terrain (110k) - one directional light 30 fps
Terrain (110k) - one point light 22 fps
Terrain (110k) - one of each 26 fps (!)

...just curious - gismo ;-)