Lumen Light performance outside of it's range?

I was just wondering if a lumen light has any performance impact outside of its range.
What I mean is If you have say 2 areas and each area has one lumen point light whose radius does not extent outside of the area. Would it effectively have the same performance as a single lumen light that spans both areas? i.e. each poly is affected by only one light in both examples.

Is this right? Or is there some aspect of the lights that extend beyond their radius?