Planetside - players distribution and does it lag like hell.?

I heard that The MMOFPS Planetside can support thousands of players at the same time, over a large battle field area. My guess is that there is a system that like in WoW where there are a few thousand people in the server, but you only get the info from those that are a set distance from you or a specified area and all the rest are ignored . But i was wondering if Planetside gets super laggy as WoW when there are about a few hundred people in Orgrimmar ,or is there a system that prevents that kind of lagg. What is the average "player collision" ( how many players do you usually directly interact with while you are playing). I honestly can't believe that a smooth FPS gameplay can be achieved with 1000 people lagging all around the server. I know it depends on about a 1000 of things how the server is set up and how much a player will be affected by lag but still -1000 players!!!


Thanks.