How Big is too Big for a Map?

[Mudbill]

I think size is irrelevant. It matters more on poly-count, as in the amount of polygons the models in the area use. For example if you place several hundreds of grunts next to each other, you'll probably drop in performance. If I remember correctly, the grunt has just over 2000 polygons, whereas a normal chair may only use 200.

I think the ways Amnesia try to handle too much rendering at once is to hide whatever isn't visible, however that might be miscalculated if it doesn't meet certain requirements. I don't really know what these requirements are or how to properly set up a level that it can utilize this feature, but it should be very much possible. As you said, the L-shaped corridors allow the game to separate the rooms and completely disable them until they're in use. If you cramp everything up, I can imagine this feature being disabled so that it doesn't de-render visible assets. I think the article also mentioned that you should patch everything up properly, because a single hole in the walls or floors can also prevent this feature from running.

Other than that, I don't know exactly how to prevent such performance issues. Of course you can go the manual way and disable/enable entities as you move through the level, but it might be tedious. However if you have certain models with very high poly-counts, consider disabling them whenever the player is away. A single grunt can have the effect of 10 chairs.