Currently I am build a map and it's proving to be rather large. I was wondering how large I can actually go before I need to be worrying about splitting into parts or sections. In the past I have just estimated and gone "yeah, this seems like a nice spot to break off" and flown with it.
Here's what I am dealing with: I am creating a multi-player Source map in EP2 that will be played on Garry's Mod. It is within the horror genre which cries for massive amounts of entity setups. It is currently split into 3 areas, forest, town, wasteland and a half built metro (which is being built so not actually included to be the 4th area yet).
I have split the areas and optimized using hint brushes and area portals, not to mention huge amounts of 'Nodraw' on areas you can't see and therefore, the frame-rate is not an issue at all. In hammer I'm getting a number of issues like taking 30 seconds to load the map, and the map actually failing to load so I'm having to copy my entire .vmf data to the converted .vmx.
I know the entity limit in Source is ~4000 according to Valve Developer. However the question is, how many is optimal for this kind of map or series of maps? At what point should I be splitting the map into separate sections? And how would I go about transitioning a multi-player Co-op map?