Irrlicht Engine

Hi all,

i'm an irrlicht newbies and i have a question.
What is the best way to manage a terrain (a map)?

I must create a terrain mesh and load it as Octree?
Or i must split it in many little terrain load them separately?

Or there is another more performing method?

A friend of mine said me that when he load a little terrain the FPS decrease incredibly, he think is an irrlicht bug. Is true?

That depends on which terrain you use. what you want to do with it, etc. The usual terrain scene node based on a heightmap will not work properly with an octree IMHO. But it features dynamic LOD for better frame rates.
For split terrains you should check on of the tiled terrain scene nodes which do also some culling on the terrain tiles.