terrain performance with heighfield collider

Hi. I've got a few questions about the heightfield collider in OgreODE, with reference to PLSM terrain. Firstly, how is the terrain loaded into the engine? Does it load all at once, or is it streamed?

I tried loading a 513x513 PLSM page into the Novodex physics engine, and there was a drop in fps by a factor of 80. What kind of performance drop would ODE suffer?

None, as terrain is not loaded into memory. Ode only need a 'getHeightAt' method against terrain.