but to answer your question, if you tell processing to draw something, it will draw it.  whether it's at 100, 100 or 10000, 10000, it will be drawn, and will consume CPU.  if you feel you need to conserve CPU, then check if something is off the edge of the screen and don't draw it if so.

back to Nest -- if you mark something as .visible = false, it will skip its draw() loop completely.  it will still perform its update() loop.  so, if you detect an object as being off-screen, and then set .visible = false, that will help to keep your sketch running smoothly.